Body Systems Past Papers Flashcards
- In a homeostatic regulatory system, a change in the external environment is detected by a(n)
a. effector
b. sensor
c. integrating centre
d. stimulus
b. sensor
- Change in variable -> detected by sensory receptor cells (sensor).
- Receptor cells send signals to CNS & endocrine glands -> Integrating centre -> Afferent pathway
- CNS & endocrine cells send impulses to muscle & secretory cells (effector).
- Effectors correct change in variable -> stimulates sensory receptor cells.
- Receptor cells send signals to CNS & endocrine glands -> stop sending electrical impulses to effector cells. -> Stops further fluctuation of controlled variable.
- Transport of ions by the Na+:K+ATPase pump
a. involves the exchange of intracellular K+ for extracellular Na+
b. is only dependent on the concentration of K+ ions
c. results in the exchange of 3 Na+ ions for every 2 K+ ions
d. is a passive process
c. results in the exchange of 3 Na+ ions for every 2 K+ ions
The Na+/K+-ATPase enzyme is active (i.e. it uses energy from ATP). For every ATP molecule that the pump uses, three sodium ions are exported and two potassium ions are imported.
Na+/K+ pump -> gradient maintenance -> actively transports ions so everything else can diffuse passively (down conc. gradient)
Sympathetic ganglia differ from parasympathetic ganglia in
a. the type of cholinesterase present at neuronal synapses
b. their anatomical location c. the neurotransmitter released by the pre-ganglionic neuron
d. the types of acetylcholine receptors present on post-ganglionic neuron cell bodies
d. the types of acetylcholine receptors present on post-ganglionic neuron cell bodies ??
1.Parasympathetic: Preganglionic fibre -> ganglion -> releases acetylcholine (ACh) -> activates nicotinic (N2) receptor -> action potential moves along postganglionic fibre -> releases acetylcholine (ACh) -> activates muscarinic (M) receptor.
2.Sympathetic:
i) Symapthetic:
Preganglionic fibre -> ganglion
-> releases acetylcholine (ACh)
-> activates nicotinic (N2) receptor
-> action potential moves along postganglionic fibre
-> releases norepinephrine (NA)
-> activates (alpha/beta) adrenergic receptor
The extracellular matrix found in connective tissue is synthesized by
a. adipocytes
b. fibroblasts
c. macrophages
d. mast cells
b. fibroblasts
- Cells within Extracellular matrix
i) Cell types:
> Fibroblasts -> Main cell type -> Synthesises extracellular matrix
>Apipocytes
>Macrophage cells
>Mast cells
ii) Exctracellular matrix:
Ground substance
Tissue (extracellular fluid)
Fibres:
->Collagen
->Reticular
->Elastic
The vessels that are most distensible and therefore hold the major proportion of the intravascular blood are the
a. arterioles
b. elastic arteries
c. muscular arteries
d. veins
• Veins -> capacitance vessels
Classified according to size (diameter)
Small: <2mm
Medium: 2-9mm
Large: >9mm -> Eg. superior & inferior vena cavae
Low pressure
Easily distensible (capacitance)
Thin walls
Predominant tunica externa
Valves -> aid blood flow
• Systemic venous system -> 65-70% blood distribution.
• Arteries: High pressure -> thick muscular walls Small lumen Maintains shape -> elastic Resilient No valves
- The popliteal pulse can be palpated
a. at the wrist
b. in the neck
c. on the dorsum of the foot d. posterior to the knee
d. posterior to the knee
- Cephalic -> Head
- Jugular -> Neck
- Brachium -> Arm
- Popliteal fossa -> Back of knee
- Axillary fossa -> Arm pit
- Veins contain valves which
a. are folds of the tunica intima
b. permit blood flow in both directions
c. enable blood to pool in the lower extremities
d. allow backflow of blood
a. are folds of the tunica intima
Tunica intima -> Innermost layer of blood vessels • Veins: Low pressure -> thin walls Wide lumen Less elastic & resilient Valves -> prevent backflow.
- In an infant, erythropoiesis will occur in
a. all bone marrow
b. only red bone marrow
c. the spleen
d. the yolk sac and liver
d. the yolk sac and liver
• Erythropoiesis:
Production of erythrocyte (RBCs)
Requires:
- Enthyropoietin (EPO) -> hormone
->Initiates erythropoiesis
- Iron
- Vitamin B12 & folic acid (B9)
- Intrinsic factor
- Amino acids
Location:
- Foetus ->Early in yolk sac, then liver & spleen
->Later -> bone marrow
- Infant -> All bone marrow
- Adult -> Red bone marrow only
-->Ribs, vertebrae, skull, upper ends -> long bones.
>Can digress & erythropoiesis occur in all parts of adult body when necessary.
- Monocytes are white blood cells that mainly
a. function outside the blood
b. defend against bacteria
c. activate immunological defence mechanisms
d. initiate the inflammatory response
a. function outside the blood
Monocytes:
- Agranulocytes
- 2-10% WBCs
- Structure:
Largest white cell
Up to 20 micrometres diameter
Large kidney/Horse-shoe shaped nucleus
Extensive cytoplasm
- Function:
Little function -> blood
Migrate out -> circulation after 3-4 days
Tissue macrophages
>>Several months-yrs
Phagocytic
- In haemostasis, the first event that occurs after blood vessel damage is
a. clotting
b. platelet activation
c. platelet adhesion
d. vasoconstriction
d. vasoconstriction
• Haemostasis:
- Vasoconstriction – blood vessels
- Platelet adhesion & aggregation
- Clotting -> coagulation
• Platelets:
- Structure:
Small
Oval
No nucleus
2-3 micrometres diameter
Contain granules
- Functions:
Megakaryocyte cytosplasm
Production controlled by
>>No. circulating platelets -> negative feedback
>>Thrombopoietin (TPO) release -> incr. platelet no.s
Lifepsan 7-10 days
Variety functions -> essential -> haemostasis
Platelets
a. have a diameter of 20-30 µm
b. contain granules
c. remain in the circulation for 120 days
d. are formed in the liver
b. contain granules
• Platelets:
- Structure:
Small
Oval
No nucleus
2-3 micrometres diameter
Contain granules
- Functions:
Megakaryocyte cytosplasm
Production controlled by
>>No. circulating platelets -> negative feedback
>>Thrombopoietin (TPO) release -> incr. platelet no.s
Lifepsan 7-10 days
Variety functions -> essential -> haemostasis
- Systemic blood pressure is
a. the product of total peripheral resistance and heart rate
b. the product of total peripheral resistance and stroke volume
c. the product of total peripheral resistance and cardiac output
d. none of the above
c. the product of total peripheral resistance and cardiac output
Blood pressure (BP) is determined by cardiac output (CO) and total peripheral resistance (TPR) BP = CO x TPR.
Cardiac output (CO) is affected by two factors, the heart rate (HR) and the stroke volume (SV) CO = HR x SV,
Therefore BP = HR x SV x TPR
Baroreceptors are located
a. in both the carotid artery and aortic arch
b. only in the carotid artery c. only in the pulmonary artery
d. in both the carotid artery and the pulmonary artery
a. in both the carotid artery and aortic arch
Baroreceptors are pressure sensors located in the carotid sinus & and the aortic arch
The heart rate of trained individuals is generally
a. the same as untrained individuals
b. the same as untrained individuals, but their cardiac output is higher
c. lower than untrained individuals, but their cardiac output is higher
d. lower than untrained individuals, but their cardiac output is the same
c. lower than untrained individuals, but their cardiac output is higher
Non-Athlete Resting ; Excersised ;
Athlete Resting ;
Excersised
CO (L/min) ~5 ~20 ~5.5 ~30 HR (bpm) 75 190 55 180 SV (ml) 65 105 100 165
The ECG trace
a. is generally described in terms of the P, Q, R, S and T waves
b. can be used to measure blood pressure
c. detects only sinoartial node events
d. detects only muscle contraction
??
ECG detects electrical responses -> heart
» Profile -> accumulative representation -> action potentials across heart.
» Reflects stages of cardiac cycle:
i. ) Atrial contraction / relaxation
ii. ) Ventricular contraction / relaxation
iii. ) Conduction velocities -> electrical signals
P-wave:
»Atrial depolarization & contraction
QRS Complex:
»Spread -> electrical signal
>Causes ventricular myocyte depolarisation
& contraction
-»Arterial relaxation event masked -> larger ventricular event.
T-wave:
»Ventricle repolarisation & relaxation
QT interval:
»Time from initiation -> ventricular contraction -> end -> ventricular relaxation.
The rate of blood flow through the cardiovascular system is
a. independent of gravity
b. independent of the viscosity of blood
c. highest during the diastolic phase of the cardiac cycle
d. regulated by blood vessel tone
d. regulated by blood vessel tone
Chronic heart failure
a. affects only the left side of the heart
b. arises when venous return is reduced, but cardiac output is normal
c. may lead to peripheral oedema
d. can be treated using β-adrenoceptor agonists
c. may lead to peripheral oedema
• Chronic Heart Failure:
Inadequate cardiac output
-> Despite venous return
Due to:
Decline in contractility
Inability to develop forceful contracture
Insufficient blood causes overworking of heart -> leads to stretching of heart muscle over time so stretched thin chmabers insufficient generation of force on contraction.
Diastole:
> Inability to fill
-> Stiff, thick chambers
Insufficient blood causes overworking of heart
»_space; Leads to stretching of heart muscle over time
Stretched thin chambers -> insufficient generation of force on contraction
Systole:
> Inability to contract
-> Stretched, thin chambers
Caused by:
> Muscle damage Eg. CAD
> Additional work of heart Eg. Hypertension
> Valve defects
Causes:
> Breathlessness & fatigue
> Left Ventricular Failure:
-> Fluid accumulation -> lungs due to congestion of veins in lungs
> Right Ventricular Failure:
-> Fluid accumulation -> especially in tissues of legs & abdominal organs due
to incr. systemic capillary pressure.
- The left lung has
a. one fissure
b. two bronchopulmonary segments
c. three lobes
d. four secondary bronchi
• Left Lung:
- Narrower
a. one fissure - Longer
- 2 lobes
Superior (upper lobe)
Inferior (lower lobe) - 1 fissure
Oblique
Alveoli
a. number about 250 million in each lung
b. form part of the respiratory membrane
c. contain cuboidal epithelial cells called type I pneumocytes
d. consist mainly of type II pneumocytes
a. number about 250 million in each lung
Pneumocytes -> Cells in alveoli
Alveoli
Site -> gas exchange
Surrounded by network of capillaries
150-250 mill per lung
Blood Supply
Structure:
Type I Alveolar Cell:
»_space; Simple squamous epithelium
> Forms wall of alveolus
Type II Alveolar Cell:
»_space; Secretes Surfactant
Macrophage:
»_space; Phagocytozes small inhaled particles & bacteria
Capillary
Respiratory membrane
»_space; Epithelium -> Type I alveolar cell
»_space; Basement membrane -> Type I alveolar cell
»_space; Basement membrane -> Capillary
»_space; Endothilium -> Capillary
-» Basement membranes often fused together.
The Hering-Breuer reflex
a. is triggered by a decrease in plasma pH b. involves afferent impulses carried to the respiratory centres by the phrenic nerve c. reduces the duration of inspiration d. is triggered when the respiratory rate is elevated
• Hering-Breuer Reflex: - Prevents over-inflation of lungs - Stretch receptors Visceral pleura Bronchioles Alveoli - Impulses sent via vagus nerve Pneumotaxic centre - Duration of inspiration shortened.
In the rhythmicity centre of the brain, E neurons
a. are activated by I neurons b. are located in the dorsal respiratory group
c. regulate activity of the phrenic nerve
d. are only active during forced breathing
??
• Neural Control of Ventilation:
- Chemoreceptors detect changes in PO2, PCO2 & pH
-> Send impulses / signals
Vagus (CN X) & Glossopharyngeal (CN IX) nerves
(Afferent pathway)
- Impulses transported -> Vagus (CN X) & Glossopharyngeal (CN IX) nerves
Respiratory Centres of Brain Stem
- Respiratory Centres of Brain stem
-> Send impulses / signals
Phrenic, intercostal & other nerves
(Efferent pathway)
- Impulses transported -> Phrenic, intercostal & other nerves
Muscles in ventilation
• Respiratory Centres:
- Group of neurons -> Brain stem
- Send impulses to muscles of ventilation
- Medullary Rhythmicity Area
Dorsal Respiratory Group (DRG)
Sets rhythm, stimulates muscles of quiet inspiration
Ventral Respiratory Group (VRG)
Involved in forced inspiration & expiration
- Pneumotaxic area (Pons)
Influences DRG by regulating duration of inspiration.
The respiratory centre is divided into three major groups, two in the medulla and one in the pons. The two groups in the medulla are the dorsal respiratory group and the ventral respiratory group.
The dorsal respiratory group (DRG) initiating inspiration (inhalation)
-> End-point for sensory information arriving from the pontine respiratory group, and from two cranial nerves – the vagus nerve, and the glossopharyngeal nerve.
- The appearance of chest over-inflation in chronic obstructive pulmonary disease (COPD) is due to
a. decreased vital capacity b. increased residual volume
c. infection and inflammation d. reduced compliance
?
Carbon monoxide (CO) is poisonous because it
a. binds to haemoglobin and displaces oxygen
b. displaces oxygen in the lungs, preventing haemoglobin from taking up oxygen
c. binds to globin chains to prevent pH buffering
d. binds to globin chains to give toxic carbamino compounds
?
select the ONE INCORRECT option from those provided
Parasympathetic nerves
a. have short post-ganglionic fibres
b. release acetylcholine as a neuroeffector transmitter
c. have pre-ganglionic fibres that originate in the cranial and cervical regions of the spinal cord
d. have stimulatory effects on the gastrointestinal tract
c. have pre-ganglionic fibres that originate in the cranial and cervical regions of the spinal cord
- -> Originates -> spinal chord & base of brain
- > Not cranial region of spinal chord.
Parasympathetic Nervous system -> Spinal cord & base of brain.
- Outflow from CNS: Parasympathetic -> Cranial & sacral
- Preganglionic fibre:
-> Long - Ganglionic transmitter:
-> ACh (N2) - Postganglionic fibre:
-> Short - Neuroeffector transmitter:
Parasympathetic -> ACh (M)
The parasympathetic nervous system (PNS) controls homeostasis and the body at rest and is responsible for the body’s “rest and digest” function.
select the ONE INCORRECT option from those provided
The adrenal medulla
a. contains chromaffin cells
b. possesses nicotinic receptors
c. secretes aldosterone into the circulation
d. is innervated by the sympathetic nervous system
?
c. secretes aldosterone into the circulation
ii) Adrenal medulla:
-> Sympathetic Nervous system
Preganglionic fibre -> adrenal medulla
-> releases acetylcholine (ACh)
-> stimulates chromaffin cell
-> makes epinephrine
-> moves along postganglionic fibre
-> releases epinephrine
->sent into circulatory system
-> stimulates adrenergic receptors of heart
-> incr. heart rate.
select the ONE INCORRECT option from those provided
Smooth muscle
a. forms sphincters in the urinary tract
b. is located in the airway walls
c. alters the diameter of blood vessels
d. is involved in gastrointestinal movement
a. forms sphincters in the urinary tract
- Smooth
Forms walls of organs, blood vessels & airways
Gastrointestinal movement
Alters diameters -> airways & blood vessels
- Short, fusiform (narrow at ends) cells
- Non striated (not striped)
- Single central nucleus
- Innervated -> autonomic nervous system
Skeletal muscle forms sphincters in urinary tract
select the ONE INCORRECT option from those provided
Connective tissue is comprised of
a. macrophages
b. adipocytes
c. mast cells
d. reticulocytes
d. reticulocytes
Connective tissue
- Structural framework for body
- Supports surrounds & interconnects tissues
- Protects delicate organs
- Transports fluids & dissolved materials
- Stores energy reserves
- Defence -> microorganisms
- Classification of connective tissue:
1.Specialised connective tissue
2.Connective tissue proper
-> 1. Loose areolar/irregular
Variety of cells- Fibroblasts, adiposcytes, macrophages (transient)
->2. Dense irregular connective tissue:
->Few cells - Mainly fibroblasts
->3. Dense regular connective tissue
-> Few cells
- Mainly fibroblast
- Fibroblasts, adiposcytes, macrophages (transient)
select the ONE INCORRECT option from those provided
In the coronary circulation, the coronary sinus receives blood from the
a. anterior cardiac vein
b. great cardiac vein
c. middle cardiac vein
d. small cardiac vein
?
select the ONE INCORRECT option from those provided
The lymphatic system
a. is involved in defence against infection
b. returns excess interstitial fluid to the vascular system
c. does not contain valves
d. includes blind-ended capillaries
c. does not contain valves
- >Process of elimination
Lymphatic circulation: - Network lymphatic vessels - Lymph - Lymphatic tissues & organs Defence mechanisms Drains interstitial fluid
- Removal of excess interstitial fluid:
1. Fluid -> out of capillary-> interstitial space -> arterial end of capillary
2. Fluid -> into capillary -> venous end of capillary
15% fluid remains -> interstitial space
->Enters lymphatic system -> lymphatic capillary -> becomes lymph
->Returned to blood - Lymph capillaries -> Blind-ended tubes
- > adjacent -> capillary beds
Lymphatic drainage:
Lymph capillaries -> Lymph vessels -> Lymph nodes -> Lymph trunks
i) Thoracic duct
ii) Right lymphatic duct
Lymphatic drainage: - RHS head, neck , thorax & upper limb Right lymphatic duct Right subclavian vein - Rest of body Thoracic duct Left subclavian vein
select the ONE INCORRECT option from those provided
The pericardial cavity is
a. found between the visceral and parietal pericardia
b. deep to the parietal pericardium
c. found between the parietal and fibrous pericardia
d. superficial to the visceral pericardium
b. deep to the parietal pericardium
• Fibrous Pericardium: Characteristics: - Inelastic sac -> dense tissue - Inferior fusion -> diaphragm - Superior infusion -> large vessels Function: - Prevents overfilling of heart - Anchors position
• Serous pericardium: Characteristics: - Double-layered serous membrane - Lies -> deep within -> fibrous pericardium - Contains: 1. Parietal pericardium: Lines inner surface -> fibrous pericardium 2. Visceral pericardium: Tightly adhered -> surface of heart 3. Pericardial cavity: Space between parietal & visceral layers Contains tissue fluid. Function: Prevents friction.
• Heart wall: - 3 layers: i) Endocardium: Inner layer -> Endothelium ii) Myocardium: Middle layer -> Cardiac muscle iii) Epicardium: Outer layer -> Visceral pericardium
select the ONE INCORRECT option from those provided
Red blood cell production is stimulated by
a. bleeding
b. low altitude
c. low oxygen levels in the blood
d. erythropoietin released from the kidney
b. low altitude
• Erythrocyte Homeostasis:
Low conc O2
Detected by kidneys -> stimulates incr. production -> erythropoietin
Detected -> stem cells -> incr. production of RBCs
More RBCs -> higher O2 transportation capacity -> incr. O2 conc.
Causes of hypoxia (low O2 conc)
- Incr. excersise
- High altitude
- Smoking
- Bleeding
Production of erythrocyte: Production of RBCs required Triggers kidneys -> release erythropoietin hormone Erythropoietin -> acts on stem cells Instigates specialisation of stem cell -> production -> RBCs Proerythroblast -> immature cell -> bone marrow Matures -> Erythroblast Normoblast -> containing full haemoglobin conc. -->Constant production of haemoglobin during these stages Normoblast ejects nucleus -> reticulocyte Reticulocyte still contains some ribosomal RNA >If Reticulocyte released -> circulation prematurely -> still some ability to produce haemoglobin. Small number in circulation -> later mature -> RBCs Lots of reticulocytes ->Anaemia Erythrocyte (RBC)
select the ONE INCORRECT option from those provided
Granulocytic white blood cells
a. are nucleated
b. contain granules
c. generally survive in the blood for a short time
d. include lymphocytes
d. include lymphocytes
i) Granulocytes
- Neutrophils
- Eosinophils
- Basophils
ii) Agranulocytes
- Lymphocytes
- Monocytes
Neutrophils: - 50-70% of WBCs -> most common - Structure: 9-15 micrometres diameter Distinctive nucleus >>2-5 lobes >>Granular cytoplasm - Function: 1st line defence -> bacterial infection Phagocytic Mobile Circulate -> blood -> approx. 10hrs Major component -> pus
Eosinophils:
- 2-4% of WBCs
- Structure:
10-12 micrometres diameter
Bilobular nucleus
- Function:
Circulate -> blood -> approx. 8-12 hrs
>>Migrate -> tissues
Lifespan approx. 1-3 days
Release toxic compounds
Eg. NO & cytotoxic enzymes
Allergies
>>Athsma
Combat -> parasitic infections
Attack bacteria, protozoa, debris
Basophils:
- >1% WBCs -> least common
- Structure:
8-10 micrometres diameter
Bilobed “S” shaped nucleus
>>Large cytoplasmic granules
Granules
>>Histamine
>>Heparin
- Function:
Inflammatory response
Unknown lifespan
Possible precursors -> mast cells
>>Share common bone marrow precursor
select the ONE INCORRECT option from those provided
The initiation phase of coagulation includes the following elements
a. activation of FX to FXa
b. Factor Va as a co-factor
c. Factor VII
d. tissue factor
d. tissue factor
• Coagulation:
- Conversion -> soluble plasma protein -> insoluble rigid polymer -> fibrin
Fibrinogen -> soluble
Thrombin -> enzyme -> polymerisation
>>Fibrinogen -> Fibrin.
Fibrin -> insoluble
Factor XIII -> stabilises Fibrin
Initaiation of coagulation:
- Extrinsic pathway
Tissue factor
»Binds to Factor VII -> Tissue Factor-FVIIa complex
»_space;Binds -> FX -> activates transformation -> FXa
- Intrinsic pathway
Factor IX & co-factor VIII
»_space;Binds -> FX -> activates transformation -> FXa
Slower -> extrinsic pathway
- Common pathway
Prothrombinase
Comprised FXa & FVa as co-factor
»_space;Binds -> Prothrombin -> produces -> thrombin
»_space;Thrombin -> converts -> Fibrinogen -> Fibrin
select the ONE INCORRECT option from those provided
Neutrophils
a. are the least common type of white blood cell
b. have a lobular shaped nucleus
c. engulf and destroy bacteria
d. are approximately 12 µm in diameter
a. are the least common type
Neutrophils: - 50-70% of WBCs -> most common - Structure: 9-15 micrometres diameter Distinctive nucleus >>2-5 lobes >>Granular cytoplasm - Function: 1st line defence -> bacterial infection Phagocytic Mobile Circulate -> blood -> approx. 10hrs Major component -> pus
select the ONE INCORRECT option from those provided Capillary fluid exchange
a. has a null point which is towards the arterial end of a capillary network
b. is dependent upon a decline in blood pressure from the arterial end to the venous end of the capillary network
c. enables high rates of net reabsorption to be maximised at the venous end of the capillary network d. is determined by the balance of osmotic and hydrostatic fluids across a capillary network
a. has a null point which is towards the arterial end of a capillary network
• Dynamics of capillary exchange:
Arterial end
High hydrostatic pressure -> forces fluid out capillary network
»_space; Opposed -> high osmotic potential gradient
Capillary Hydrostatic Pressure (CHP) -> 35mmHg
Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg
-» CHP > BCOP
-» Net filtration pressure -> +10mmHg
»_space; Forces fluid & dissolved substances out -> capillary network
Significant rate of filtration -> 24 L/day
Venous end
Hydrostatic pressure decline -> incr. distance -> heart
Same osmotic potential
Capillary Hydrostatic Pressure (CHP) -> 18mmHg
Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg
-» CHP < BCOP
-» Net Filtration Pressure -> -7mmHg
»_space;Movement of fluid -> into capillary network
Significant Rate of reabsorption -> 20.4 L/Day
Net difference in water -> Rate of filtration & absorption
Collected -> Lymphatic System
Centre -> Capillary Network
Approx. centre -> capillary network
->Equal values -> CHP & BCOP -> Net filtration pressure = 0.
-> No net movement -> fluid.
Max filtration pressure always greater -> max absorption pressure
»_space; Point at which net filtration pressure = 0
-> further towards venous end -> capillary
-» More filtration than absorption along capillary.
¬-» Enables provision -> tissues with required molecules over greater
distance -> capillary network
> Rapid reabsorption -> molecules & waste products -> venous end.
select the ONE INCORRECT option from those provided
Physiological responses to hypotension include
a. increased sympathetic stimulation of the heart
b. an increase in the blood volume
c. inhibition of the cardiovascular centres in the brain
d. an elevation of blood pressure triggered by hormones
c. inhibition of the cardiovascular centres in the brain ?
Look at treatments & what they cause -> actual hypotension woukd be causing opposite effect of that as treatment inhibiting/counteracting it. Also look at risks associated and what causes those risks to occur.
• Hypertension:
Affects nearly one billion
One of the main causes -> premature death.
Nearly 8 million fatalities per year
Types:
- Primary Hypertension
(Essential / Idiopathic)
Unknown medical cause
Links:
Genetic predisposition
Alcohol consumption
Obesity
Lack of excersise
Diabetes
Intrauterine environment
- Secondary Hypertension
Known medical cause
1) Kidney Disease:
Incr. Angiotensin II
» Vasoconstriction & expansion -> cellular fluid
2) General endocrine disorders
Eg. Diabetes, Cushing’s
3) Adrenal medulla disease (Phaeochroocytoma)
Excessive adrenaline secretion
Treatment:
- Inhibit angiotensin II production -> Angiotensin-Converting-Enzyme (ACE)
» Prevents renal absorption -> Na+/H2O
> Prevents incr. blood volume
- Ibhibition -> Angiotensin II induced vasoconstriction -> Angiotensin II receptor
blocker.
»_space; Inhibitd membrane cardiac / vascular depolarizoation
> Decr. CO -> vasodilation.
- Calcium-channel blocker / thiazide diuretic
»_space; Incr. loss -> Na+ & H2O
> Decreases fluid volume, venous return & cardiac output.
- Reduce TBR -> inhibition -> noradrenaline action.
- Alpha-adrenoreceptor Antagonists (alpha-Blockers)
Reduce TBR -> inhibition -> noradrenaline action.
- Beta-adrenoreceptor Antagonists (beta-Blockers)
Decr. CO2,
Decr. central activity -> Symapthetic nervous system
Decr. release -> Renin
-» Favourable secondary actions
Risks:
- Atherosclerosis
- Stroke / Cerebrovascular Accident
- Heart Failure
- Renal Failure
- Aneurysms
select the ONE INCORRECT option from those provided
Bradycardia
a. can be caused by elevated plasma potassium concentration
b. is defined as an increase in heart rate
c. occurs from ionic defects in control of the ventricular action potential
d. can result in ventricular arrhythmias
b. is defined as an increase in heart rate
• Arrhythmias:
Deviation of heart’s normal sinus (SAN) rhythm.
Relatively rare
-> 1 in 5000-10000
Found -> young individuals ; <25yrs
Many arise
-> Defects in ion channels regulating ventricular action potentials
Cause spontaneous multiple depolarizations
»_space; Ventricular arrythmias
Produce sustained abnormal rhythm
Asymptomatic
Palpitations
Dizziness
Syncope
Heart Failure
Sudden Death
1. Bradycarida:
Slow Rhythm (<60bpm)
Causes:
Slowed signal -> sinus bradycardia
Pause / sinus arrest
Blockage
>> Due to SAN / conducting tissue damage
Treatment:
Artificial pacemaker
select the ONE INCORRECT option from those provided
Heart rate is
a. described as a chronotropic variable
b. increased by acetylcholine
c. increased by glucagon
d. increased by noradrenaline
a. described as a chronotropic variable
The heart rate is influenced by chronotropic variables!
• Chronotropic Effect:
- Influence effecting heart rate.
• Innervation of Heart:
1. Cardioregulatory centre & chemoreceptors -> medulla oblongata
Via -> Sensory Nerve Fibres
->> Baroreceptors -> wall of internal carotid artery
->> Carotid body chemoreceptors
->> Baroreceptors -> Aorta
2. Adrenal Medulla
i) Via -> Parasympathetic nerve fibres
->> Sinoatrial (SA) Node
ii) Via -> Sympathetic nerve fibres
->> Heart
3. Adrenal Medulla
Via -> Sympathetic nerve fibres -> adrenal gland
>Release adrenaline/noradrenaline -> circulation
->>Heart
• Regulation of blood pressure:
- Decreased blood pressure detected by baroreceptors.
- Baroreceptors send signals along glosso-pharyngeal nerve to the Medulla oblongata -> brain.
- Medulla oblongata sends incr. impulses along autonomic nerves to heart blood vessels.
- Incr. no of impulses -> incr. cardiac output & vasoconstriction of heart blood vessels. -> Blood pressure increases to optimal level.
- Increased blood pressure detected by baroreceptors.
- Baroreceptors send signals along glosso-pharyngeal nerve to Medulla oblongata.
- Medulla oblongata decr. impulses along autonomic nerves to blood vessels of heart.
- Blood vessels decr. cardiac output & vasoconstriction -> preventing further fluctuation of pressure.
select the ONE INCORRECT option from those provided
Long-QT syndrome
a. leads to arrhythmias
b. is caused by ion channel gene defects
c. can be detected on an ECG recording
d. originates from defects in the sinoatrial node
d. originates from defects in the sinoatrial node
Long QT syndrome (LQTS) is a disorder of the heart’s electrical activity, usually caused by a faulty gene inherited from a parent.
It can cause sudden, uncontrollable, dangerous arrhythmias
select the ONE INCORRECT option from those provided
Essential (idiopathic) hypertension
a. is associated with obesity b. is linked to alcohol intake c. may be predetermined by the intrauterine environment d. is caused by elevated aldosterone levels
d. is caused by elevated aldosterone levels
- >Other anseers imply causes ; or associations however this states this is the cause ; despite cause is unknown.
Essential hypertension (also called primary hypertension or idiopathic hypertension) is the form of hypertension that by definition has no identifiable cause. It tends to be familial and is likely to be the consequence of an interaction between environmental and genetic factors.
select the ONE INCORRECT option from those provided
The conductive portion of the respiratory tract is concerned with
a. filtering the air
b. gas exchange
c. humidifying the air
d. warming the air
b. gas exchange
The conducting portion consists of the air-transmitting passages of the nose, nasopharynx, larynx, trachea, bronchi and bronchioles. This part of the respiratory system serves to filter, warm and humidify air on its way to the lungs.
select the ONE INCORRECT option from those provided
Structures that enter the lung at the hilum include
a. bronchial arteries
b. phrenic nerve
c. primary bronchus
d. pulmonary artery
- Hilum of lung:
Located -> mediastinal surface
Region of entry -> lungs for blood vessels, lymphatics, nerves & bronchi.
select the ONE INCORRECT option from those provided
During exercise the muscles of forced inspiration are recruited; these include the
a. pectoralis minor
b. rectus abdominus
c. serratus anterior
d. sternocleidomastoid
b. rectus abdominus
• Inspiration:
- Active process
- At rest:
Diaphragm (75%)
External intercostal muscles (25%)
Contracted diaphragm flattens
-> Vertical diameter of thorax increased.
External intercostals elevate ribs -> incr. Anterior Posterior & Transverse
diameters.
- Forced:
Pectoralis major
Pectoralis minor
Scalenes
Serratus anterior
Sternocleidomastoid
Assist -> rib elevation
-> Incr. speed & amount of movement
select the ONE INCORRECT option from those provided
Surfactant
a. helps to decrease surface tension in the lungs
b. is a mixture of phospholipids
c. is less concentrated in smaller alveoli
d. is secreted by type II alveolar cells
Type II Alveolar Cell:
»_space; Secretes Surfactant
b. is a mixture of phospholipids
Pulmonary surfactant is a mixture of lipids and proteins which is secreted by the epithelial type II cells into the alveolar space.
The main function of pulmonary surfactants is to reduce the surface tension at the air/liquid interface in the lungs.
As the alveoli increase in size, the surfactant becomes more spread out over the surface of the liquid. This increases surface tension effectively slowing the rate of expansion of the alveoli. This also helps all alveoli in the lungs expand at the same rate, as one that expands more quickly will experience a large rise in surface tension slowing its rate of expansion. It also means the rate of shrinking is more regular, as if one reduces in size more quickly the surface tension will reduce more, so other alveoli can contract more easily than it can. Surfactant reduces surface tension more readily when the alveoli are smaller because the surfactant is more concentrated.
select the ONE INCORRECT option from those provided
Gas exchange occurs by diffusion and is dependent upon
a. co-ordinated blood and air flow
b. how insoluble gases (oxygen and carbon dioxide) are in blood
c. short diffusion distance
d. large moist surface area
b. how insoluble gases (oxygen and carbon dioxide) are in blood
select the ONE INCORRECT option from those provided
Peripheral chemoreceptors act in response to
a. a change in pH
b. hypercapnia
c. hypoxia
d. lung inflation (stretch)
Hypercapnia, also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood
select the ONE INCORRECT option from those provided
The main symptoms of asthma are
a. bronchoconstriction
b. chronic productive cough c. oedema of airway mucosa d. secretion of mucus
?
select the ONE INCORRECT option from those provided
Restrictive lung diseases such as fibrosis
a. exhibit increased lung compliance
b. are characterised by the development of excess connective tissue
c. are associated with decreased vital capacity
d. may be caused by inhaled environmental and occupational pollutants
?
A process that requires cellular energy to move a substance against its concentration gradient is called
a. active transport
b. diffusion
c. facilitated transport
d. passive transport
a. active transport
Compared with intracellular fluid, the extracellular interstitial fluid concentration of
a. chloride is low
b. potassium is high
c. protein is low
d. sodium is low
c. protein is low
Extrarcellular fluid has :
- Lower K conc
- Higher Na conc
- Slightly higher (but sill low) conc of Ca
- Higher conc. Cl
- Lower Org conc
- Lwer Protein conc
The reference plane that divides the body into superior and inferior regions is the
a. coronal plane
b. frontal plane
c. sagittal plane
d. transverse plane
d. transverse plane
• Anatomical position: Position of the upright body -> arms at sides -> palms facing forwards. - Anterior (Ventral): Front / Underside - Posterior (Dorsal) Behind/ Upperside/back - Superior Towards the head - Inferior Towards the feet - Medial The core/centre - Lateral Towards the side/ away from core/centre - Proximal Closer towards the trunk - Distal Further from the trunk - Coronal/frontal plane: Divides into front & back planes -> Anterior/ventral & posterior/dorsal - Horizontal/transverse plane Divides into top & bottom planes -> Above & below waist -> Superior & Inferior - Midsagittal plane Divides into right & left halves -> medial & lateral
Epithelial cells are bound to the basement membrane by
a. desmosomes
b. gap junctions
c. hemidesmosomes
d. tight junctions
c. hemidesmosomes
• Intercellular junctions:
- Specialised areas of cell mem -> bind cells to one another.
- Types of intercellular junction:
Desosomes:
Strong
Join adjacent cells
Resist stretching & twisting.
Hemidesosomes:
Stabilising
Attach cells to basement mem
Anchor to underlying tissue
Tight junctions
Binds adjacent cells -> interlocking proteins
Prevents passage of water & solutes between cells
Found on Apical side of cells
Eg. Digestive tract -> Prevents digestive fluids passing between epithelial cells.
Gap junctions:
Interlocking mem proteins (connexons) bind cells together
Connexons – central pore enabling movement of small molecules & ions between cells
Cardiac muscle
The blood vessel layer that consists of simple squamous epithelium and subendothelial connective tissue is the tunica
a. adventia
b. externa
c. intima
d. media
c. intima
Endothelium -> simple squamous epithelium
Basal lamina of epithelial cells
Subendothelial connective tissue
- Tunica media:
Smooth muscle fibres -> loose connective tissue
May contain elastic fibres - Tunica adventitia:
Connective tissue
Merges -> surrounding connective tissue
May contain vaso vasroum
- Blood that is low in oxygen moves from the right side of the heart to the lungs through the
a. foetal circulation
b. portal circulation
c. pulmonary circulation
d. systemic circulation
• Foetal circulation: - Oxygen & nutrients received from placenta Umbilical vein - Bypasses non-functional lungs 3 shortcuts: i) Ductus venosus >> Umbilical vein -> inferior vena cava ii) Foramen ovale >> Right -> left atria iii) Ductus arteriosus >> Pulmonary trunk -> arch of aorta.
• Portal circulations: - Blood drains -> one capillary bed ->Vein -> 2nd capillary bed ->Heart. Eg. Hypophyseal portal system Hypothalmus -> pituitary gland Eg. Hepatic portal system Gastrointestinal tract -> liver. The right-hand side of the heart collects deoxygenated blood from the body and pumps it to the lungs (to collect more oxygen). This is called pulmonary circulation.
Systemic circulation:
High pressure -> arterial
Transports oxygenated blood -> LHS heart -> body tissues
Returns deoxygenated blood – RHS heart
Blood is prevented from flowing back into the left atrium by the
a. aortic valve ‘
b. bicuspid valve
c. pulmonary valve
d. tricuspid valve
b. bicuspid valve
• Blood flow through heart:
- Deoxygenated blood from body tissues
- > Superior & Inferior vena cava -> right atrium
2. Right atrium
- > Tricuspid (right atrioventricular) valve -> right ventricle.
3. Right ventricle
- > Pulmonary semilunar valve -> pulmonary trunk & arteries.
4. Pulmonary trunk & arteries
- > Lungs -> Oxygenated -> Pulmonary veins.
5. Pulmonary veins
- > Left atrium
6. Left atrium
- > Bicuspid (mitral/left atrioventricular valve) -> Left ventricle
7. Left ventricle
- > Aortic semilunar valve -> aorta.
8. Aorta
- > Body tissues.
Haematopoiesis is the term which describes the production of
a. all types of blood cell
b. haemoglobin
c. platelets
d. red blood cells
a. all types of blood cell
•Haematopoiesis/Haemopoiesis:
Process -> formation -> blood cells
All cells produced -> 1 haematopoietic stem cell
Self-renewing
Differentiates -> different cells -> depending on requirements of body
i) Common myeloid progenitor -> production -> all cells except lymphocytes
ii) Common lymphoid progenitor -> production -> lymphocytes
• Erythropoiesis:
Production of erythrocyte (RBCs)
• Haemoglobin:
Transports O2 & CO2
Synthesis begins -> proerythroblast
65% -> erythroblast
35% -> reticulocyte
280 million per RBC
15g/dl
4 subunits:
2 alpha & 2 beta
Each contains haem
>Bound -> globin -> long polypeptide chain
Ferrous iron atom Fe2+ at centre of each subunit
>>Can reversibly bind -> O2
Eosinophils
a. are inactive during an allergic response
b. are the least common white blood cell
c. are the largest white blood cell
d. have a bilobed nucleus
Eosinophils:
d. have a bilobed nucleus
Eosinophils:
- 2-4% of WBCs
- Structure:
10-12 micrometres diameter
Bilobular nucleus
- Function:
Circulate -> blood -> approx. 8-12 hrs
>>Migrate -> tissues
Lifespan approx. 1-3 days
Release toxic compounds
Eg. NO & cytotoxic enzymes
Allergies
>>Athsma
Combat -> parasitic infections
Attack bacteria, protozoa, debris
The coagulation phase of haemostasis is initiated by
a. factor X
b. prothrombin
c. thrombin
d. tissue factor
d. tissue factor
Coagulation:
- Conversion -> soluble plasma protein -> insoluble rigid polymer -> fibrin
Fibrinogen -> soluble
Thrombin -> enzyme -> polymerisation
>>Fibrinogen -> Fibrin.
Fibrin -> insoluble
Factor XIII -> stabilises Fibrin
Initaiation of coagulation:
- Extrinsic pathway
Tissue factor
»Binds to Factor VII -> Tissue Factor-FVIIa complex
»_space;Binds -> FX -> activates transformation -> FXa
- Intrinsic pathway
Factor IX & co-factor VIII
»_space;Binds -> FX -> activates transformation -> FXa
Slower -> extrinsic pathway
- Common pathway
Prothrombinase
Comprised FXa & FVa as co-factor
»_space;Binds -> Prothrombin -> produces -> thrombin
»_space;Thrombin -> converts -> Fibrinogen -> Fibrin
- Haemolytic disease of the newborn can develop with an
a. Rh -ve foetus and Rh +ve mother
b. Rh -ve foetus and Rh -ve mother
c. Rh +ve foetus and Rh -ve mother
d. Rh +ve foetus and Rh +ve mother
• Rh [D] Blood group:
c. Rh +ve foetus and Rh -ve mother
- Rh -ve -> Antigen present
- Rh +ve -> Antigen absent
» Rh -ve -> does not usually contain anti-Rh [D] antibodies
>Requires sensitisation -> exposure -> Rh +ve RBCs
Transfusion
Pregnancy/ birth
->Rh -ve mother & Rh +ve baby
->Haemolytic disease -> newborn -> HDN
The short-term control of blood pressure mainly involves
a. aldosterone production
b. changes in the heart rate
c. fluid loss
d. Na+ loss from the kidney
b. changes in the heart rate
• Pulmonary Circulation:
- Decr. O2 & Incr. CO2 -> constriction -> arterioles. Response & Regulation of Blood Pressure:
Homeostasis:
- Altered Blood pressure / volume
Physical stress
Eg. Trauma, high temp, etc.
Chemical changes
Eg. Decr. O2 / decr. pH / Incr. CO2 / Incr. vasodilatory metabolites
Increases tissue activity / Intrinsic Control
- Inadequate blood pressure & flow
»Autoregulation:
Decr. resistance & incr. blood flow
> Homeostasis returned.
- Insufficient Autoregulation:
Stimulates receptors -> sensitive to systemic changes -> blood pressure /
Chemistry.
Activates cardiovascular centres -> Central Nervous System
Elevates Blood pressure -> Short Term
»_space;Stimulation -> heart rate & peripheral vasoconstriction
–» Sensory Nervous System.
Return -> Homeostasis.
- Baroreceptors
a. are only located in the aortic arch
b. are only located in the carotid artery
c. detect changes in blood metabolites
d. detect changes in vascular pressure
d. detect changes in vascular pressure
• Baroreceptors:
Wall -> internal carotid artery
Aorta
Baroreceptors & Control -> Blood Flow:
• Inadequate Blood supply / Decr. Blood Pressure:
- Inhibition -> baroreceptors
Activation
Cardioacceloratory Centre
Vasomotor Centres
Inhibition
Cardioinhibitory Centre
>> Incr. Cardiac Output & Heart Rate
- Vasoconsriction
• Rise -> Blood Pressure:
- Stimulation -> Baroreceptors
Activation
Cardioinhibitory Centre
Inhibition
Cardioacceloratory Centre
Vasomotor Centres
>> Decr. Cardiac Output & Heart Rate
- Vasodilation.
- The heart
a. beats about 1,000 times per day
b. is an endocrine gland
c. is innervated by sympathetic nerve fibres but not by parasympathetic nerve fibres
d. is not affected by drugs that are used to treat hypertension
b. is an endocrine gland
Avg. HR per min = 75
So (75 x 60 ) x 24 = 108,000•
Endocrine glands are ductless glands of the endocrine system that secrete their products, hormones, directly into the blood. The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands.
Innervation of Heart: 1. Cardioregulatory centre & chemoreceptors -> medulla oblongata Via -> Sensory Nerve Fibres ->> Baroreceptors -> wall of internal carotid artery ->> Carotid body chemoreceptors ->> Baroreceptors -> Aorta 2. Adrenal Medulla i) Via -> Parasympathetic nerve fibres ->> Sinoatrial (SA) Node ii) Via -> Sympathetic nerve fibres ->> Heart 3. Adrenal Medulla Via -> Sympathetic nerve fibres -> adrenal gland >Release adrenaline/noradrenaline -> circulation ->>Heart
The cardiac cycle
a. describes the integration of electro-mechanical coupling of the heart
b. is generally described in terms of the P, Q, R, S and T periods
c. takes approximately 3 milliseconds to complete
d. takes place in the sinoartial node
??
Cardiac electro-mechanical coupling is known to contribute to sudden cardiac death, a significant public health issue, but its role in the intact human heart
Described in terms of P-wave, QRS complex, T-wave & QT interval
Cardiac cycle occurs throughout heart.
The cardiac output of a non-athletic individual is
a. generally higher than that of a trained individual during exercise
b. generally the same as that of a highly-trained individual at rest
c. increased by 10-fold during modest exercise
d. independent of their heart rate
b. generally the same as that of a highly-trained individual at rest
Untrained -> Rest ; Excersised
–> Trained -> Rest ; Excersised
CO (L/min) ~5 ~20 ~5.5 ~30
CO = HR x SV
- Coronary artery disease is
a. caused by angina
b. managed by drugs that increase cardiac output
c. most commonly caused by atherosclerosis of a coronary artery
d. treated with drugs that cause vasoconstriction
• Ischaemic Heart
c. most commonly caused by atherosclerosis of a coronary artery
Disease (Coranary Heart Disease -> CAD)
Leading cause of death -> Developed world
30% Males
23% Females
Common cause:
Atherosclerosis -> coronary artery
Most frequent -> Left anterior interventricular artery
Occurs in Left ventricle
Insufficient Blood flow to myocardium
» Angina Pectoris (ischemia-induced pain)
-»Mediated by endogeneous vasodilators
» Results -> myocardial infarction
-» Death of heart muscle within 20 mins
- Surfactant is secreted in the alveoli by
a. goblet cells
b. macrophages
c. type I alveolar cells
d. type II alveolar cells
d. type II alveolar cells
Alveoli
Site -> gas exchange
Surrounded by network of capillaries
150-250 mill per lung
Blood Supply
Structure:
Type I Alveolar Cell:
»_space; Simple squamous epithelium
> Forms wall of alveolus
Type II Alveolar Cell:
»_space; Secretes Surfactant
Macrophage:
»_space; Phagocytozes small inhaled particles & bacteria
Capillary
Respiratory membrane
»_space; Epithelium -> Type I alveolar cell
»_space; Basement membrane -> Type I alveolar cell
»_space; Basement membrane -> Capillary
»_space; Endothilium -> Capillary
-» Basement membranes often fused together.
In the nose; one of the functional adaptations, the mucosa; contain goblet cells which produce mucous to trap particles.
The tubercle of the fifth rib articulates with the
a. body of the sternum
b. body of the thoracic vertebra
c. manubrium of the sternum
d. transverse process of the thoracic vertebra
- Bony Thorax:
Forms skeleton of chest wall
d. transverse process of the thoracic vertebra
->Says attached, specifically articulated to sternum & thoracic vertebra
Components:
12 pairs ribs
-> 7 true pairs
-> 3 false pairs
-> 2 floating
12 thoracic vertebrae
Sternum
- Sternum:
Breast bone
Components:
Manubrium
Body
Xipisternum
- Ribs:
Differ -> shape & size
Slope downwards & forwards
Attached by head & tubercle -> thoracic vertebrae
Ribs 1-10 attached by costal cartilage -> sternum
- Thoracic Vertebrae:
Head of rib articulates with body of thoracic vertebra
Tubercle of rib articulates with transverse process of thoracic vertebra
- Intercostal muscles:
Span intercostal spaces
External intercostals
Superficial layer
Fibres run supero-lateral to infero-medial
-> Tubercles to costochondral junction -> (Downward-diagonally from
shoulder to core - / )
Internal intercostals
Middle layer
Fibres run infero-lateral to supero-medial
-> At angles to ends of intercostal spaces. -> (Upward-diagonally from
hip to core - \ )
Innermost intercostals
Innermost layer
- Intercostal Vessels & Nerves:
Intercostal spaces
Supply muscles. Adjacent skin & pleura.
- Diaphragm:
Dome shaped-skeletal muscle with central tendon
Attached:
Xiphisternum
Costal Margin
11th & 12th ribs
Left & Right Crus
-> Arise -> Lumbar vertebrae
Innervated -> phrenic nerve
Most important muscle -> ventilation.
Structures / components:
Skeletal muscle -> outside
Centrally-placed tendon
-> No body attachments
- The vertical diameter of the thorax is increased by
a. contraction of the diaphragm
b. contraction of the external intercostal muscles
c. relaxation of the diaphragm
d. relaxation of the external intercostal muscles
a. contraction of the diaphragm
• Incr. Thoracic Volume:
- Incr. Vertical diameter
Contraction of diaphragm incr. vertical diameter
Responsible for 75% incr. thoracic capacity
- Incr. Anterior Posterior diameter
Elevation of ribs incr. Anterior Posterior diameter
-> (Joint with Transverse Diameter)
Responsible for 25% thoracic capacity.
Elevation of ribs -> external end -> makes them more horizontal & pushes sternum forward (pump handle movement)
Incr. AP diameter
- Incr. transverse diameter
Elevation of ribs incr. transverse diameter
-> (Joint with Transverse Diameter)
Responsible for 25% thoracic capacity.
Many of the ribs
Lowest near their middle
Rise at each end
Eg. Bucket handle
Rise of middle of rib -> movement away from midline of body
Transversally widens chest (Left -> Right)
• Inspiration:
- Active process
- At rest:
Diaphragm (75%)
External intercostal muscles (25%)
Contracted diaphragm flattens
-> Vertical diameter of thorax increased.
External intercostals elevate ribs -> incr. Anterior Posterior & Transverse
diameters.
- Forced:
Pectoralis major
Pectoralis minor
Scalenes
Serratus anterior
Sternocleidomastoid
Assist -> rib elevation
-> Incr. speed & amount of movement
The amount of air that could be exhaled following a normal exhalation is the
a. expiratory reserve volume b. residual volume
c. tidal volume
d. vital capacity
?
- The receptors that detect changes in PCO2 and pH but are unresponsive to changes in PO2 are
a. known as peripheral chemoreceptors
b. located in the aortic bodies
c. located in the carotid bodies
d. located just beneath the ventral surface of the medulla
d. located just beneath the ventral surface of the medulla
??
• Central Chemoreceptors: - Located -> Medulla oblongata of brainstem - Respond to changes in PCO2 & pH • Peripheral Chemoreceptors: - Detect changes -> PO2, PCO2 & pH - Aortic Bodies Located -> Aortic Arch Innervated -> Vagus (CN X) - Carotid Body Located -> Common Carotid Artery Innervated -> Glossopharyngeal (CN IX)
• Respiratory Centres:
- Group of neurons -> Brain stem
- Send impulses to muscles of ventilation
- Medullary Rhythmicity Area
Dorsal Respiratory Group (DRG)
Sets rhythm, stimulates muscles of quiet inspiration
Ventral Respiratory Group (VRG)
Involved in forced inspiration & expiration
- Pneumotaxic area (Pons)
Influences DRG by regulating duration of inspiration.
In the control of breathing, the regulatory centre that is located in the pons and promotes inspiration is the
a. aortic body
b. apneustic centre
c. pneumotaxic centre
d. rhythmicity centre
c. pneumotaxic centre
• Respiratory Centres:
- Group of neurons -> Brain stem
- Send impulses to muscles of ventilation
- Medullary Rhythmicity Area
Dorsal Respiratory Group (DRG)
Sets rhythm, stimulates muscles of quiet inspiration
Ventral Respiratory Group (VRG)
Involved in forced inspiration & expiration
- Pneumotaxic area (Pons)
Influences DRG by regulating duration of inspiration
If the total pressure of a mixture of gases was 760 mmHg and its composition was 20% oxygen, 0.04% carbon dioxide, 75% nitrogen and 5% water vapour, then the partial pressure of oxygen would be
a. 20 mmHg
b. 120 mmHg
c. 152 mmHg
d. 740 mmHg
c. 152 mmHg
- > 20% of 760?
Emphysema is
a. associated with a decrease in macrophage infiltration into the lung parenchyma
b. caused by an increase in the surface area of the alveoli
c. related to an inhibition of 1-antitrypsin activity
d. reversible
?
indicate the ONE INCORRECT option from those provided.
- Examples of transcellular fluids include
a. blood plasma
b. synovial fluid
c. urine
d. vitreous humour
c. urine
The fluids that are not inside cells, but are separated from plasma and interstitial fluid by cellular barriers (e.g., cerebrospinal fluid, synovial fluid, pleural fluid).
Transcellular fluids are also a component of ECF and are found in the cerebrospinal column, pleural cavity, lymph system, joints, glandular secretions, and eyes
Synovial fluid is found in the cavities of synovial joints. It reduces friction between the articular cartilage of synovial joints during movement & is a small component of the transcellular fluid
The vitreous humor is a transparent, colorless, gelatinous mass that fills the space in the eye between the lens and the retina. It is surrounded by a layer of collagen called vitreous membrane separating it from the rest of the eye.
Blood plasma liquid component of blood that normally holds the blood cells in whole blood in suspension; this makes plasma the extracellular matrix of blood cells. It makes up about 55% of the body’s total blood volume. It is the intravascular fluid part of extracellular fluid (all body fluid outside cells).
indicate the ONE INCORRECT option from those provided.
- Examples of transcellular fluids include
a. blood plasma
b. synovial fluid
c. urine
d. vitreous humour
c. urine
The fluids that are not inside cells, but are separated from plasma and interstitial fluid by cellular barriers (e.g., cerebrospinal fluid, synovial fluid, pleural fluid).
Transcellular fluids are also a component of ECF and are found in the cerebrospinal column, pleural cavity, lymph system, joints, glandular secretions, and eyes
Synovial fluid is found in the cavities of synovial joints. It reduces friction between the articular cartilage of synovial joints during movement & is a small component of the transcellular fluid
The vitreous humor is a transparent, colorless, gelatinous mass that fills the space in the eye between the lens and the retina. It is surrounded by a layer of collagen called vitreous membrane separating it from the rest of the eye.
Blood plasma liquid component of blood that normally holds the blood cells in whole blood in suspension; this makes plasma the extracellular matrix of blood cells. It makes up about 55% of the body’s total blood volume. It is the intravascular fluid part of extracellular fluid (all body fluid outside cells).
indicate the ONE INCORRECT option
provided.
Parasympathetic nerves
a. have long pre-ganglionic fibres
b. have their origins in the sacral region of the spinal chord
c. innervate skeletal muscle
d. utilise acetylcholine as a neuroeffector transmitter
c. innervate skeletal muscle
- Parasympathetic nerves comprise the autonomic nerves -> innervate smooth & cardiac mucle & involved
in subconscious activity
2. Parasympathetic Nervous system -> Spinal cord & base of brain. Outflow from CNS: Parasympathetic -> Cranial & sacral Parasympathetic -> Long - Ganglionic transmitter: Parasympathetic -> ACh (N2) - Postganglionic fibre: Parasympathetic -> Short - Neuroeffector transmitter: Parasympathetic -> ACh (M)
indicate the ONE INCORRECT option
Smooth muscle cells can be distinguished from skeletal muscle cells because they
a. are innervated by the autonomic nervous system
b. are short and fusiform in shape
c. are striated
d. possess a single, centrally located nucleus
c. are striated
- Muscle:
c. are striated
- Produces movement -> specialised for contraction
- 3 types – skeletal , smooth & cardiac.
Similarirties - Elongated parallel to axis of contraction
- Numerous mitochondria
-Contractile elements
1. Skeletal Moves & stabilises skeleton Forms sphincters in digestive & urinary tracts -> controls urges to pee etc. Involved in respiration - Long cylindrical cells - Striated (striped) - Multinucleated (multiple per cell) - Innervated -> somatic nervous system
- Smooth
Forms walls of organs, blood vessels & airways
Gastrointestinal movement
Alters diameters -> airways & blood vessels
- Short, fusiform (narrow at ends) cells
- Non striated (not striped)
- Single central nucleus
- Innervated -> autonomic nervous system
indicate the ONE INCORRECT option
- Simple squamous epithelium lines
a. arteries
b. bronchi
c. serous cavities
d. the chambers of the heart
??
- Simple squamous
Exchange of nutrients & gases -> Blood vessels & alveoli - Non-keratinised stratified squamous
Protection -> Oral cavity & oesophagus - Keratinised stratified Squamous
Waterproof protection/barrier -> Skin - Simple cuboidal epithelium
Secretion & absorption -> Glands & kidney tubules - Simple columnar epithelium
Absorption & secretion -> Gastrointestinal tract
–> also have microvilli -> Enabling absorption of nutrients. - Pseudostratified ciliated columnar epithelium with goblet cells
Mucociliary escalator -> produce mucous -> particles inhaled -> trapped in mucous.
-> Cilia moves mucous upwards to back of throat for swallowing.
-> Trachea & large respiratory airways.
-> Also has cilia & goblet cells.
Trachea appears stratified -> some cells don’t reach free surface -> All touch
basement mem.
Serous cavities are cavities lined by serous membrane serous cavity a coelomic cavity, like that enclosed by the pericardium, peritoneum, or pleura, not communicating with the outside of the body and lined with a serous membrane,(mesothelium)
indicate the ONE INCORRECT option
Compared with veins, arteries
a. appear to have a larger lumen
b. have thicker walls
c. are more resilient
d. maintain their shape
a. appear to have a larger lumen
indicate the ONE INCORRECT option
Arteries found in the upper limb include the
a. brachial artery
b. carotid artery
c. ulnar artery
d. radial artery
b. carotid artery
- > Carotid = neck
• Major arteries: - Arm: Axillary -> Shoulder Brachial -> Upper arm Radial -> Lateral Ulnar -> Medial - Leg: External iliac -> Hip area Femoral -> Upper leg Popliteal -> Back of knee Anterior tibial - Core: Right common carotid -> Right -> neck Left common carotid -> Left -> neck Brachiocephalic trunk -> Lungs Right subclavian -> Right -> under collarbone Left subclavian -> Left -> under collarbone Aortic arch -> Main part of heart Descending thoracic aorta -> Down inside lower end of rib cage -> spine Abdominal aorta -> Abdominal -> inside spine Common iliac -> Top of hip External iliac -> Lower hip -> top of leg Internal iliac -> Backbone
indicate the ONE INCORRECT option
The right atrium receives blood from the
a. coronary sinus
b. inferior vena cava
c. pulmonary veins
d. superior vena cava
c. pulmonary veins
The coronary sinus is a collection of smaller veins that merge together to form the sinus, located along the heart’s posterior surface between the left ventricle and left atrium
It drains deoxygenated blood into the right atrium of the heart. so it can be pumped to the lungs to
acquire oxygen.
Pulmonary veins are responsible for carrying oxygenated blood from the lungs back to the left atrium of the heart.
indicate the ONE INCORRECT option
Haemoglobin
a. cannot be synthesised in the mature red blood cell
b. consists of two alpha and two beta subunits
c. synthesis begins in the proerythroblast
d. transports O2 from tissues to lungs
d. transports O2 from tissues to lungs
• Haemoglobin:
Transports O2 & CO2
Synthesis begins -> proerythroblast
65% -> erythroblast
35% -> reticulocyte
280 million per RBC
15g/dl
4 subunits:
2 alpha & 2 beta
Each contains haem
>Bound -> globin -> long polypeptide chain
Ferrous iron atom Fe2+ at centre of each subunit
>>Can reversibly bind -> O2
• Structure of RBCs:
- Biconcave disc
Enables easy passage through vessels
- 7-8 micrometeres -> diameter
- Foldable & flexible -> deforms easily
- Stable
- No organelles
more room for haemoglobin
- Function:
Transportation -> oxygen & CO2
- Life span
120 days
> Broken down & recycled.
-> So no ability to produce haemoglobin as no organelles/ nucleus
Production of erythrocyte:
Production of RBCs required
Triggers kidneys -> release erythropoietin hormone
Erythropoietin -> acts on stem cells
Instigates specialisation of stem cell -> production -> RBCs
Proerythroblast -> immature cell -> bone marrow
Matures -> Erythroblast
Normoblast -> containing full haemoglobin conc.
–>Constant production of haemoglobin during these stages
Normoblast ejects nucleus -> reticulocyte
Reticulocyte still contains some ribosomal RNA
>If Reticulocyte released -> circulation prematurely -> still some ability to
produce haemoglobin.
Small number in circulation -> later mature -> RBCs
Lots of reticulocytes
->Anaemia
Erythrocyte (RBC)
indicate the ONE INCORRECT option
White blood cells are
a. also known as leukocytes
b. capable of amoeboid movement
c. not able to migrate out of the bloodstream
d. nucleated
c. not able to migrate out of the bloodstream
• White blood cells: Also known -> Leukocytes Nucleated Act mainly outside tissues In-transit -> sites of activity Can migrate out of bloodstream -> extravastation (diapedesis) Capable -> amoebid movement Attracted -> specific chemical stimuli 2 groups: i) Granulocytes - Neutrophils - Eosinophils - Basophils ii) Agranulocytes - Lymphocytes - Monocytes Neutrophils, eosinophils & monocytes -> phagocytosis Functions: - Defence -> pathogens - Toxin & waste removal - Removal -> damaged cells
indicate the ONE INCORRECT option
An individual with blood group B
a. can accept blood from a person with A antigens on their red blood cells
b. can donate blood to people with the B antigen on the surface of their blood cells
c. will have the B antigen on the surface of their red blood cells
d. will have anti-A antibodies in their plasma
a. can accept blood from a person with A antigens on their red blood cells
A antigens on RBCs = A Blood Type -> A blood type cells produce anti-B antibodies which would then cause individual’s blood to clot by agglutination
In addition, their B Blood type cells will produce Anti-A antibodies to cause agglutination of type A cells for elimination.
indicate the ONE INCORRECT option
Erythropoietin is released
a. during anaemia
b. when blood flow to the kidneys is increased
c. when the O2 content of the air in the lungs decreases
d. when the respiratory surface of the lungs is damaged
b. when blood flow to the kidneys is increased ??
• Erythrocyte Homeostasis:
Low conc O2
Detected by kidneys -> stimulates incr. production -> erythropoietin
Detected -> stem cells -> incr. production of RBCs
More RBCs -> higher O2 transportation capacity -> incr. O2 conc.
Causes of hypoxia (low O2 conc)
- Incr. excersise
- High altitude
Production of erythrocyte:
Production of RBCs required
Triggers kidneys -> release erythropoietin hormone
Erythropoietin -> acts on stem cells
Instigates specialisation of stem cell -> production -> RBCs
Proerythroblast -> immature cell -> bone marrow
Matures -> Erythroblast
Normoblast -> containing full haemoglobin conc.
–>Constant production of haemoglobin during these stages
Normoblast ejects nucleus -> reticulocyte
Reticulocyte still contains some ribosomal RNA
>If Reticulocyte released -> circulation prematurely -> still some ability to
produce haemoglobin.
Small number in circulation -> later mature -> RBCs
Lots of reticulocytes
->Anaemia
Erythrocyte (RBC)
indicate the ONE INCORRECT option
The rate of blood flow is
a. always higher in arteries than veins
b. controlled by the radius of the blood vessel
c. dependent upon the viscosity of blood
d. influenced by the length of the blood vessel
a. always higher in arteries than veins
Blood flow determined:
- Resistance -> R
- Pressure difference -> P
F = ▲P / ▲R
Determined by:
->> L = length of vessel
->> r = radius of vessel
->> ꞃ = fluid viscosity
>>(protein conc.)
R = (8Lꞃ) / (πr4)
F = ▲P((πr4) / (8Lꞃ))
indicate the ONE INCORRECT option
Fluid exchange across a capillary bed
a. enables net reabsorption to be maximised at the venous end of the capillary b. has a null point which is towards the venous end of the capillary network
c. is dependent upon higher blood pressure at the venous end of the capillary compared with the arterial end
d. is impaired in people with hypertension leading to oedema
c. is dependent upon higher blood pressure at the venous end of the capillary compared with the arterial end ‘
- > This would mean more molecules still forced out of blood into extracellular fluid, further decr. vol. of fluid & dissolved subs. in capillaries & hence no time for reabsorption of waste products for removal.
• Dynamics of capillary exchange:
Arterial end
High hydrostatic pressure -> forces fluid out capillary network
»_space; Opposed -> high osmotic potential gradient
Capillary Hydrostatic Pressure (CHP) -> 35mmHg
Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg
-» CHP > BCOP
-» Net filtration pressure -> +10mmHg
»_space; Forces fluid & dissolved substances out -> capillary network
Significant rate of filtration -> 24 L/day
Venous end
Hydrostatic pressure decline -> incr. distance -> heart
Same osmotic potential
Capillary Hydrostatic Pressure (CHP) -> 18mmHg
Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg
-» CHP < BCOP
-» Net Filtration Pressure -> -7mmHg
»_space;Movement of fluid -> into capillary network
Significant Rate of reabsorption -> 20.4 L/Day
Net difference in water -> Rate of filtration & absorption
Collected -> Lymphatic System
Centre -> Capillary Network
Approx. centre -> capillary network
->Equal values -> CHP & BCOP -> Net filtration pressure = 0.
-> No net movement -> fluid.
Max filtration pressure always greater -> max absorption pressure
»_space; Point at which net filtration pressure = 0
-> further towards venous end -> capillary
-» More filtration than absorption along capillary.
¬-» Enables provision -> tissues with required molecules over greater
distance -> capillary network
> Rapid reabsorption -> molecules & waste products -> venous end.
indicate the ONE INCORRECT .
The heart rate is
a. decreased by the actions of acetylcholine
b. described as an inotropic variable
c. increased by the actions of noradrenaline
d. increased by the actions of glucagon
b. described as an inotropic variable
• Chronotropic Effect:
- Influence effecting heart rate.
• Inotropic effects:
Effects which alter the contractility of the heart
Negative chronotropic effect:
Slows Heart Rate
Eg. Acetlycholine
->> Via positive end -> muscarinic (ACh)-receptor gated K-channels
Component of ‘vagal tone’
Positive chronotropic effect:
Increase Heart Rate
Eg. Noradrenaline & adrenaline
->> Via stimulation -> hyperpolarisation-activated ion channels
In addition to its metabolic effects, glucagon is considered to increase heart rate and contractility, stimulation of glucagon receptors causes adenylyl cyclase activation and the consequent increase in 3′,5′-(cAMP) production.
indicate the ONE INCORRECT
Tachycardia
a. arises from defects in the ventricular action potential
b. can be asymptomatic
c. involves slowing of the heart beat
d. leads to shortness of breath
c. involves slowing of the heart beat
• Arrhythmias:
Deviation of heart’s normal sinus (SAN) rhythm.
Relatively rare
-> 1 in 5000-10000
Found -> young individuals ; <25yrs
Many arise
-> Defects in ion channels regulating ventricular action potentials
Cause spontaneous multiple depolarizations
»_space; Ventricular arrythmias
Produce sustained abnormal rhythm
Asymptomatic
Palpitations
Dizziness
Syncope
Heart Failure
Sudden Death
- Tachycardia:
Fast Rhythm (>100bpm)
Sinus Tachycardia
Innapropriate Sinus Tachycardia (IST)
Invlolves:
» Caffeine
» Amphetamines
» Overactive thyroid gland -> SNS
Non-sinus Tachycardia
-> Addition of abnormal inpulses -> normal cycle
> Uncontrolled twitching / quivering -> muscle fibres (fibrils)
> Blood not removed from heart -> ventricular fibrillation
> Sudden cardiac death
Caused by:
» Automaticicity (enhanced pacemaker)
» Triggered Beats (Early / delayed depolarization)
» Re-entry Activity / Circus Activity (Conduction profile defects)
» Conduction Block
»Heart Damage
indicate the ONE INCORRECT
Long-QT Syndrome
a. can be associated with syncope
b. generates cardiac arrhythmias
c. is unrelated to ion channel gene defects
d. originates from defects in the ventricular cells
c. is unrelated to ion channel gene defects ??
Long QT syndrome (LQTS) is an inherited condition that can cause abnormal heart rhythms (arrhythmias) which affects repolarization of the heart.
Usually caused by a faulty gene inherited from a parent which affects the proteins that make up the ion channels regulating electricity in the heart. The ion channels may not work well, or there may not be enough of them, which disrupts the heart’s electrical activity.
It results in an increased risk of fainting (syncope) drowning, or sudden death
indicate the ONE
INCORRECT
Hypertension can be treated by drugs which
a. activate the angiotensin II receptor
b. increase Na+ and water loss c. inhibit angiotensin converting enzyme
d. inhibit membrane depolarization and decrease cardiac output
• Hypertension:
Affects nearly one billion
One of the main causes -> premature death.
Nearly 8 million fatalities per year
Types:
- Primary Hypertension
(Essential / Idiopathic)
Unknown medical cause
Links:
Genetic predisposition
Alcohol consumption
Obesity
Lack of excersise
Diabetes
Intrauterine environment
- Secondary Hypertension
Known medical cause
1) Kidney Disease:
Incr. Angiotensin II
» Vasoconstriction & expansion -> cellular fluid
2) General endocrine disorders
Eg. Diabetes, Cushing’s
3) Adrenal medulla disease (Phaeochroocytoma)
Excessive adrenaline secretion
Treatment:
- Inhibit angiotensin II production -> inhibition of Angiotensin-Converting-Enzyme (ACE)
» Prevents renal absorption -> Na+/H2O
> Prevents incr. blood volume
- Ibhibition -> Angiotensin II induced vasoconstriction -> Angiotensin II receptor
blocker.
»_space; Inhibitd membrane cardiac / vascular depolarizoation
> Decr. CO -> vasodilation.
- Calcium-channel blocker / thiazide diuretic
»_space; Incr. loss -> Na+ & H2O
> Decreases fluid volume, venous return & cardiac output.
- Reduce TBR -> inhibition -> noradrenaline action.
- Alpha-adrenoreceptor Antagonists (alpha-Blockers)
Reduce TBR -> inhibition -> noradrenaline action.
- Beta-adrenoreceptor Antagonists (beta-Blockers)
Decr. CO2,
Decr. central activity -> Symapthetic nervous system
Decr. release -> Renin
-» Favourable secondary actions
Risks:
- Atherosclerosis
- Stroke / Cerebrovascular Accident
- Heart Failure
- Renal Failure
- Aneurysms
indicate the ONE INCORRECT
Cartilage is found in the walls of the
a. bronchi
b. bronchioles
c. larynx
d. trachea
b. bronchioles
Bronchi
Series of tubes
Smaller in diameter
Display histological chabges
>> Decr. quantity cartilage
>> Incr. quantity smooth muscle
>> Decr. height epithelial cells
Pseudostratified ciliated columnar epithelium with goblet cells
Cartilage plates
Types:
Primary bronchus
>> Supply each lung
>> 2-3cm long
>> Right -> wider & more vertical -> left
>> C-shaped cartilages
Secondary bronchus
>> Lobar
>> Supply lobes of lung
> 3 on right
> 2 on left
>> Plates of cartilage
Tertiary bronchus
>> Segmental
>> Supply lung segments
> 10 on right
> 8 on left
>> Plates of cartilage
Bronchioles
No cartilage
Smooth muscle
>> Can constrict & dilate
Simple columnar epithelium with some goblet cells
Each has 50-80 terminal bronchioles
Types:
Terminal
>>Simple columnar epithelium with cilia
>> No goblet cells / mucous glands
>> Clara cells
> Produce surfactant
>> Each gives 2 or more respiratory bronchioles
Respiratory
>> Simple cuboidal epithelia
>Clara cells
->> Produce surfactant
>> No cilia
>> Alveoli extend from lumen
> Site -> Gas exchange
Larynx
Functions:
Maintenance -> open airway
Prevents consumed substances entering lower respiratory system.
Sound production
Involved:
Coughing
Defacecation
Structure:
Cartilaginous skeleton
>> Epiglottis
>> Thyroid cartilage (Adam’s Apple)
>> Cricoid cartilage
>>Arytenoid cartilage
Lined by memebranes
Moved using muscles
Paranasal tissues
Functions:
Warms & moistens air
Filters air
Involved -> Olfaction
Resonates sound
Trachea
Tough, flexible tube
4.5cm length
2.5cm diameter
Extends -> larynx to carina
Anterior to oesophagus
15-20 horseshoe-shaped cartilages
Keep airway open
Pseudostratified ciliated columnar epithelium with goblet cells
Dust particles -> stuck in mucus layer
Cilia move mucus layer towards mouth
>> Transports / removes dust particles
indicate the ONE INCORRECT
Structures which enter the lung at the hilum include the
a. autonomic nerves
b. bronchial arteries
c. bronchioles
d. pulmonary arteries
c. bronchioles ?
- > States bronchi only explicitly. Bronchioles may be too small / further down respiratory tract & wouldn’t need to enter lungs as attached to bronchi which already doing so.
Hilum of lung: Located -> mediastinal surface Region of entry -> lungs for blood vessels, lymphatics, nerves & bronchi.
Bronchial arteries supply high-pressure oxygenated blood to the supporting structures of the lung, including the pulmonary arteries
indicate the ONE INCORRECT
- Muscles involved in forced inspiration include the
a. internal intercostal
b. pectoralis major
c. serratus anterior
d. sternocleidomastoid
a. internal intercostal
• Inspiration:
- Active process
- At rest:
Diaphragm (75%)
External intercostal muscles (25%)
Contracted diaphragm flattens
-> Vertical diameter of thorax increased.
External intercostals elevate ribs -> incr. Anterior Posterior & Transverse
diameters.
- Forced:
Pectoralis major
Pectoralis minor
Scalenes
Serratus anterior
Sternocleidomastoid
Assist -> rib elevation
-> Incr. speed & amount of movement
indicate the ONE INCORRECT
Pulmonary surfactant
a. greatly reduces surface tension
b. increases compliance
c. is less concentrated in smaller alveoli
d. is produced by the type II alveolar cells
c. is less concentrated in smaller alveoli
Pulmonary surfactant are formed by type II alveolar cells
Greatly reduce surface tension, increasing compliance allowing the lung to inflate much more easily, reducing the work of breathing. It reduces the pressure difference needed to allow the lung to inflate.
As the alveoli increase in size, the surfactant becomes more spread out over the surface of the liquid. This increases surface tension effectively slowing the rate of expansion of the alveoli. Hence Surfactant reduces surface tension more readily when the alveoli are smaller because the surfactant is more concentrated.
- Compared with extracellular fluid, the intracellular fluid concentration of
a. organic anions is low
b. potassium is low
c. protein is high
d. sodium is high
c. protein is high
Compared to the extracellular fluid, the intracellular fluid has:
- Higher K conc.
- Lower Na conc
- Lower Ca conc. (though extracellular is still low)
- Lower Cl conc
- Higher Org conc
- Higher Protein conc.
In the autonomic nervous system sympathetic pre-ganglionic fibres
a. activate muscarinic receptors
b. are short
c. exit the spinal cord from the cranial and sacral sections
d. release noradrenaline
b. are short
- Sympathetic Nervous system -> Spinal cord
- Outflow from CNS:
Sympathetic -> Thoracic & lumbar
- Preganglionic fibre: Sympathetic -> Short - Ganglionic transmitter: Sympathetic -> ACh (N2) - Postganglionic fibre: Sympathetic -> Long - Neuroeffector transmitter: Sympathetic -> NA (alpha or beta)
Sympathetic: i) Symapthetic: Preganglionic fibre -> ganglion -> releases acetylcholine (ACh) -> activates nicotinic (N2) receptor -> action potential moves along postganglionic fibre -> releases norepinephrine (NA) -> activates (alpha/beta) adrenergic receptor.
Skin is a type of keratinised
a. pseudostratified columnar epithelium
b. pseudostratified squamous epithelium
c. simple squamous epithelium
d. stratified squamous epithelium
Examples of epithelial tissue:
d. stratified squamous epithelium
- Simple squamous
Exchange of nutrients & gases -> Blood vessels & alveoli - Non-keratinised stratified squamous
Protection -> Oral cavity & oesophagus - Keratinised stratified Squamous
Waterproof protection/barrier -> Skin - Simple cuboidal epithelium
Secretion & absorption -> Glands & kidney tubules - Simple columnar epithelium
Absorption & secretion -> Gastrointestinal tract
–> also have microvilli -> Enabling absorption of nutrients. - Pseudostratified ciliated columnar epithelium with goblet cells
Mucociliary escalator -> produce mucous -> particles inhaled -> trapped in mucous.
-> Cilia moves mucous upwards to back of throat for swallowing.
-> Trachea & large respiratory airways.
-> Also has cilia & goblet cells.
Trachea appears stratified -> some cells don’t reach free surface -> All touch
basement mem.
- The cells responsible for the synthesis and maintenance of connective tissue are
a. adipocytes
b. fibroblasts
c. macrophages
d. mast cells
- Connective tissue
- Structural framework for body
b. fibroblasts
- Supports surrounds & interconnects tissues
- Protects delicate organs
- Transports fluids & dissolved materials
- Stores energy reserves
- Defence -> microorganisms
- Cells within Extracellular matrix
i) Cell types:
> Fibroblasts -> Main cell type -> Synthesises extracellular matrix
>Apipocytes
>Macrophage cells
>Mast cells
ii) Exctracellular matrix:
Ground substance
Tissue (extracellular fluid)
Fibres:
->Collagen
->Reticular
->Elastic
- The elastic fibres found in the tunica media of conducting arteries
a. enable the vessel to constrict
b. prevent vasodilation
c. promote diffusion of gases through the vessel wall
d. withstand the pressure changes in the cardiac cycle
d. withstand the pressure changes in the cardiac cycle
- > Muscles enable constriction
- > Elastic fibres flexible therefore wouldn’t prevent distension / relaxation of walls
- > From conducting arteries -> high pressure
• Characteristics of blood vessels:
- Resilience
- Flexibility
- Constantly remain open
- Tunica media:
Smooth muscle fibres -> loose connective tissue
May contain elastic fibres
- The circulatory system in which blood passes through two capillary beds on return to the heart is the
a. foetal circulation
b. portal circulation
c. pulmonary circulation
d. systemic circulation
b. portal circulation
Pulmonary circulation: Low pressure Deoxygenated blood -> RHS heart -> lungs Oxygenated blood -> Lungs -> LHS heart Pulmonary arteries -> Low O2 Pulmonary veins -> High O2
• Portal circulations: - Blood drains -> one capillary bed ->Vein -> 2nd capillary bed ->Heart. Eg. Hypophyseal portal system Hypothalmus -> pituitary gland Eg. Hepatic portal system Gastrointestinal tract -> liver.
Hepatic portal system:
Liver:
Oxygenated blood -> LHS heart -> Abdominal aorta
-> Hepatic artery
Liver -> respiring cells
Deoxygenated blood -> RHS heart
-> Inferior vena cava (IVC)
1st Capillary beds:
Oxygenated blood -> LHS heart ->1st capillary beds
i) Stomach, pancreas, spleen & large intestine
ii) Splenic vein -> Hepatic portal vein.
iii) Small & large intestines, stomach
iv) SMV-> hepatic portal vein -> liver
Nutrients from 1st capillary beds deposited -> liver
CO2 from liver collected -> blood from 1st capillary beds
Deoxygenated blood -> RHS heart -> hepatic vein.
• Systemic circulation: Artery -> capillary -> vein • Portal circulation: Artery -> capillary -> portal vessel -> capillary -> vein.
Foetal circulation:
- Specialised
- Lungs, liver & GI tract -> not sufficiently developed -> foetus
- > Bypassed.
- Blood is prevented from flowing back into the right ventricle by the
a. aortic valve
b. bicuspid valve
c. pulmonary valve
d. tricuspid valve
d. tricuspid valve
• Heart Valves:
Prevent backflow of blood
Atrioventricular:
- Tricuspid (Right AV) valve
- Bicuspid/mitral (Left AV) valve
Between atria & ventricles
Open -> blood flow -> atria to ventricles
Anchored -> Chordae tendinae to papillary muscles.
When ventricular pressure < atrial pressure
Valve opens -> loose chordae tendinae
When ventricular pressure > atrial pressure
Valve begins to close -> pulls chordae tendinae -> papillary muscle contracts -> prevents inversion of valve -> backflow of blood.
Semilunar: - Pulmonary - Aortic Guard entrances -> aorta & pulmonary trunk Open -> force of blood -> contraction of ventricles Bloodflow -> backwards -> aorta & pulmonary trunk -> ventricular relaxation Accumulates in cusps -> shut. Prevent backflow of blood -> ventricles.
• Blood flow through heart:
- Deoxygenated blood from body tissues
- > Superior & Inferior vena cava -> right atrium
2. Right atrium
- > Tricuspid (right atrioventricular) valve -> right ventricle.
3. Right ventricle
- > Pulmonary semilunar valve -> pulmonary trunk & arteries.
4. Pulmonary trunk & arteries
- > Lungs -> Oxygenated -> Pulmonary veins.
5. Pulmonary veins
- > Left atrium
6. Left atrium
- > Bicuspid (mitral/left atrioventricular valve) -> Left ventricle
7. Left ventricle
- > Aortic semilunar valve -> aorta.
8. Aorta
- > Body tissues.
- Haemoglobin
a. is synthesised in the mature red blood cell only
b. normally consists of 2 alpha and 2 beta subunits
c. transports CO2 from lungs to tissues
d. transports O2 from tissues to lungs
b. normally consists of 2 alpha and 2 beta subunits
- > No nucleus / organelles in fully mature cell -> so cannot synthesise haemoglobin anymore.
• Haemoglobin:
Transports O2 & CO2
Synthesis begins -> proerythroblast
65% -> erythroblast
35% -> reticulocyte
280 million per RBC
15g/dl
4 subunits:
2 alpha & 2 beta
Each contains haem
>Bound -> globin -> long polypeptide chain
Ferrous iron atom Fe2+ at centre of each subunit
>>Can reversibly bind -> O2
• Structure of RBCs:
- Biconcave disc
Enables easy passage through vessels
- 7-8 micrometeres -> diameter
- Foldable & flexible -> deforms easily
- Stable
- No organelles
more room for haemoglobin
- Function:
Transportation -> oxygen & CO2
- Life span
120 days
> Broken down & recycled.
Production of erythrocyte: Production of RBCs required Triggers kidneys -> release erythropoietin hormone Erythropoietin -> acts on stem cells Instigates specialisation of stem cell -> production -> RBCs Proerythroblast -> immature cell -> bone marrow Matures -> Erythroblast Normoblast -> containing full haemoglobin conc. -->Constant production of haemoglobin during these stages Normoblast ejects nucleus -> reticulocyte Reticulocyte still contains some ribosomal RNA >If Reticulocyte released -> circulation prematurely -> still some ability to produce haemoglobin. Small number in circulation -> later mature -> RBCs Lots of reticulocytes ->Anaemia Erythrocyte (RBC)
- Structural and functional characteristics of white blood cells include
a. a lack of mobility
b. being a minor constituent of pus
c. being the first line of defence against bacterial infection
d. having a round nucleus
c. being the first line of defence
- > Mobile
- > Major cons. pus - >Leukocytes
- > many first line defence
- > Many diff shaped nuclei
• White blood cells: Also known -> Leukocytes Nucleated Act mainly outside tissues In-transit -> sites of activity Can migrate out of bloodstream -> extravastation (diapedesis) Capable -> amoebid movement Attracted -> specific chemical stimuli 2 groups: i) Granulocytes - Neutrophils - Eosinophils - Basophils ii) Agranulocytes - Lymphocytes - Monocytes Neutrophils, eosinophils & monocytes -> phagocytosis Functions: - Defence -> pathogens - Toxin & waste removal - Removal -> damaged cells
Neutrophils:
- Function:
1st line defence -> bacterial infection
Phagocytic
Mobile
Circulate -> blood -> approx. 10hrs
Major component -> pus
Eosinophils
Bilobular nucleus
Circulate -> blood -> approx. 8-12 hrs
>>Migrate -> tissues
Release toxic compounds
Eg. NO & cytotoxic enzymes
Allergies
>>Athsma
Combat -> parasitic infections
Attack bacteria, protozoa, debris
Basophils:
Bilobed “S” shaped nucleus
Inflammatory response
Monocytes:
Large kidney/Horse-shoe shaped nucleus
Migrate out -> circulation after 3-4 days
Phagocytic
Lymphocytes:
Central role -> all immunological defence mechanisms
Circulate between -> various lymphoid tissues & all other body tissues
>>Via blood & lymphatic vessels
T-cells
>>Mediate -> cell-mediated immunity
Eg. Transplant rejection
B-cells
>>Differentiate -> plasma cells
>Secrete antibodies -> humoral immunity
NK cells
>>Immune surveillance -> prevent cancer
- The red blood cells of an individual from blood group AB will have surface
a. antibodies A and B only
b. antigens A and B only
c. antigens B and anti-A antibodies only
d. antigens A and B and the Rhesus antigen
-> Antigens A & B ,
No Anti-A or Anti-B antibodies
-> Produce Anti-A & Anti-B bodies to bind to foreign bodies & cause agglutination for elimination.
Type A Surface antigen A Anti-B antibodies Type B Surface antigen B Anti-A antibodies Type AB Surface antigens A & B Neither anti-A nor anti-B antibodies Type O Neither surface antigen A or B Anti-A & anti-B antibodies Rh [D] Blood Group: Rh [D] +ve D antigen present Rh [D] -ve D antigen absent
The blood vessels that play the most important role in the regulation of blood pressure and blood flow to a tissue are the
a. arteries
b. arterioles
c. capillaries
d. veins
a. arteries
??
-> For pure reason of most contributing factors
• Arteries:
Elastic -> conducting
Continuous blood flow
Muscular -> distributing
Distribute blood -> muscles & organs
Vasodilation & vasoconstriction -> control rate of blood flow to organ
Arterioles -> resistance
Vasoconstriction & vasodilation -> control blood flow to organs
Involved -> control of blood pressure
• Veins:
Valves -> prevent backflow.
• Valves -> prevent backflow of blood -> low pressure
• Musculovenous pump -> contracts to close valves & ensure constant bloodfow
• Capillaries:
- Connect arterioles & venules -> microcirculation
- Site of gaseous exchange
- Thin walls -> lined with endothelial cells -> enable diffusion
- Fluid is normally filtered at the arterial end of the capillaries and reabsorbed at the venous end due to changes in
a. diffusion coefficient
b. plasma hydrostatic pressure
c. plasma oncotic pressure
d. tissue hydrostatic pressure
b. plasma hydrostatic pressure
• Dynamics of capillary exchange:
Arterial end
High hydrostatic pressure -> forces fluid out capillary network
»_space; Opposed -> high osmotic potential gradient
Capillary Hydrostatic Pressure (CHP) -> 35mmHg
Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg
-» CHP > BCOP
-» Net filtration pressure -> +10mmHg
»_space; Forces fluid & dissolved substances out -> capillary network
Significant rate of filtration -> 24 L/day
Venous end
Hydrostatic pressure decline -> incr. distance -> heart
Same osmotic potential
Capillary Hydrostatic Pressure (CHP) -> 18mmHg
Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg
-» CHP < BCOP
-» Net Filtration Pressure -> -7mmHg
»_space;Movement of fluid -> into capillary network
Significant Rate of reabsorption -> 20.4 L/Day
Net difference in water -> Rate of filtration & absorption
Collected -> Lymphatic System
Centre -> Capillary Network
Approx. centre -> capillary network
->Equal values -> CHP & BCOP -> Net filtration pressure = 0.
-> No net movement -> fluid.
Max filtration pressure always greater -> max absorption pressure
»_space; Point at which net filtration pressure = 0
-> further towards venous end -> capillary
-» More filtration than absorption along capillary.
¬-» Enables provision -> tissues with required molecules over greater
distance -> capillary network
> Rapid reabsorption -> molecules & waste products -> venous end.
- A heart rate of 45 beats per minute and the absence of a P wave suggest
a. damage to the sinoatrial node
b. extrasystole
c. heart block
d. ventricular fibrillation
a. damage to the sinoatrial node ??
Normal heart rate approx. 60bpm
SAN gives regular electrical pulses. If it fails, the AV node should take over. But the spontaneous rate is lower than the SAN, Hence the heart rate will be lower. impulses are also transmitted simultaneously to atria and ventricles. Hence both atria and ventricles contract simultaneously. This prevents atrial contraction from helping the ventricular filling. This can lover the stroke volume, especially in those with stiff ventricles
Ventricular fibrillation is a heart rhythm problem that occurs when the heart beats with rapid, erratic electrical impulses.
Extrasystole: A premature contraction of the heart that is independent of the normal rhythm of the heart and that arises in response to an impulse in some part of the heart other than the normal impulse from the sinoatrial (SA) node.
P-wave:
»Atrial depolarization & contraction
QRS Complex:
»Spread -> electrical signal
>Causes ventricular myocyte depolarisation
& contraction
-»Arterial relaxation event masked -> larger ventricular event.
T-wave:
»Ventricle repolarisation & relaxation
QT interval:
»Time from initiation -> ventricular contraction -> end -> ventricular relaxation.
- If end diastolic volume is 110 mL, end systolic volume is 45 mL and the time interval between successive R waves on an ECG trace is 800 ms, then cardiac output is
a. 4.9 L/min
b. 5.2 L/min
c. 8.3 L/min
d. 11.6 L/min
a. 4.9 L/min
CO = HR x SV SV = 110-45= 65ml = 6.5 x 10^-2 HR = 800ms -> 1 contraction 800 x 10^3 = 0.8s 60/0.8= 75bpm HR = 75 CO = 75 x (6.5 x 10^-2) = 4.875L/min
- The left ventricular wall is thicker than the right ventricular wall in order to
a. accommodate a greater volume of blood
b. expand the thoracic cage during diastole
c. pump a greater volume of blood
d. pump blood with greater pressure
d. pump blood with greater pressure
To distribute around body to tissues
- Atherosclerosis is often treated by administration of a(n)
a. β-adrenoceptor agonist
b. calcium channel agonist
c. organic nitrate
d. statin
b. calcium channel agonist
Risk factor associated with Hypertension & coronary heart disease, which are treated as follows:
-> “ possible treatments; where atherosclerosis risk of nayerism due to incr. blood volume enlargement etc therefore decr. blood vol more effective so CA agonist.
- Inhibit angiotensin II production -> inhibit Angiotensin-Converting-Enzyme (ACE)
» Prevents renal absorption -> Na+/H2O
> Prevents incr. blood volume- Ibhibition -> Angiotensin II induced vasoconstriction -> Angiotensin II receptor
blocker.
»_space; Inhibitd membrane cardiac / vascular depolarizoation
> Decr. CO -> vasodilation. - Calcium-channel blocker / thiazide diuretic
»_space; Incr. loss -> Na+ & H2O
> Decreases fluid volume, venous return & cardiac output. - Reduce TBR -> inhibition -> noradrenaline action.
- Alpha-adrenoreceptor Antagonists (alpha-Blockers)
Reduce TBR -> inhibition -> noradrenaline action.- Beta-adrenoreceptor Antagonists (beta-Blockers)
Decr. CO2,
- Beta-adrenoreceptor Antagonists (beta-Blockers)
Decr. central activity -> Symapthetic nervous system Decr. release -> Renin ->> Favourable secondary actions - Ibhibition -> Angiotensin II induced vasoconstriction -> Angiotensin II receptor
• Atherosclerosis:
Narrowing of vessel lumen:
Fibrous cap of dense extracellular matrix
Accumulation -> Plaque Formation:
Lipids
Macrophages
Proinflammatory mediators
White blood cells
Endothelial cells
Smooth muscle cells
»_space; Arterial remodelling & neovessels occur -> compensatory enlargement
»_space;Fragments of plaques can detach & lodge in small vessels
> Cause thrombosis
-» Restricts blood flow
> Lead to aneurysm formation & rupture
• Ischaemic Heart Disease (Coranary Heart Disease -> CAD)
Leading cause of death -> Developed world
30% Males
23% Females
Common cause:
Atherosclerosis -> coronary artery
Most frequent -> Left anterior interventricular artery
Occurs in Left ventricle
Insufficient Blood flow to myocardium
» Angina Pectoris (ischemia-induced pain)
-»Mediated by endogeneous vasodilators
» Results -> myocardial infarction
-» Death of heart muscle within 20 mins
- Each lung segment is served by a
a. lobar bronchus
b. primary bronchus
c. secondary bronchus
d. tertiary bronchus
b. primary bronchus
• Lungs: Main features: - 2 lungs - Located -> Thoracic cavity - Separated by mediastinum - Extend from neck -> diaphragm Gross Anatomy: - Trachea - Primary Bronchi - Right & Left Lungs Structure: - Conical shaped structures - Soft, spongy texture - Each lung contains: Apex (top, tip of lung) 3 surfaces Diaphragmatic (basal surafce) Costal (outside-facing surface) Mediastinal (inside surface -> facing other lung)
- The head of the third rib articulates with the
a. body of the sternum
b. body of the third thoracic vertebra
c. third costal cartilage
d. transverse process of the third thoracic vertebra
b. body of the third thoracic vertebra
- > Articulates being key word
- > Head of rib articulates -> therefore body of thoracic vertebra
- Ribs:
Differ -> shape & size
Slope downwards & forwards
Attached by head & tubercle -> thoracic vertebrae
Ribs 1-10 attached by costal cartilage -> sternum - Thoracic Vertebrae:
Head of rib articulates with body of thoracic vertebra
Tubercle of rib articulates with transverse process of thoracic vertebra - Intercostal muscles:
Span intercostal spaces
External intercostals
Superficial layer
Fibres run supero-lateral to infero-medial
-> Tubercles to costochondral junction -> (Downward-diagonally from
shoulder to core - / )
Internal intercostals
Middle layer
Fibres run infero-lateral to supero-medial
-> At angles to ends of intercostal spaces. -> (Upward-diagonally from
hip to core - \ )
Innermost intercostals
Innermost layer
- The respiratory zone of the respiratory tract
a. includes the alveolar ducts
b. includes the terminal bronchioles
c. is lined by pseudostratified ciliated columnar epithelia
d. is responsible for filtering the air
a. includes the alveolar ducts
The terminal bronchiole is the most distal segment of the conducting zone. It branches off the lesser bronchioles. Each of the terminal bronchioles divides to form respiratory bronchioles which contain a small number of alveoli.
The respiratory tract is lined with respiratory mucosa or respiratory epithelium
• Respiratory tract organised according to function: - Conductive: Filteration, warming & moistening air Conducting air into lungs Structures: Nasal cavity & paranasal sinuses Pharynx Larynx Trachea Primary bronchi Secondary bronchi Tertiary Bronchi Bronchioles Terminal Bronchioles - Respiratory: Sites of gas exchange Structures: Respiratory Bronchioles Alveolar Ducts Alveolar Sacs Alveoli
- Forced exhalation is aided by contraction of the
a. abdominal muscles
b. diaphragm
c. external intercostal muscles d. sternocleidomastoid muscles
a. abdominal muscles
• Expiration:
- At rest:
Passive process
Diaphragm
External intercostals
Relaxation of diaphragm & external intercostal muscles
- Forced:
Active process
Internal intercostals
Abdominal muscles
-> Rectus abdominis
-> External oblique
-> Internal oblique
-> Transversus abdominis
Internal & innermost intercostals depress ribs
-> Reduce size of thoracic cavity
Abdominal muscles compress abdomen & force diaphragm upwards
- Regarding respiratory capacities
a. functional residual capacity is the volume of air leaving the lungs in a normal tidal expiration
b. inspiratory capacity is the maximum amount of air inspired in a tidal inspiration c. total lung capacity is usually the same for adult males and females
d. vital capacity is the maximum amount of air that can be expired after a maximum inspiratory effor
?
- Delivery of oxygen to tissues is aided by a. decreased 2,3-DPG (2,3-diphosphoglycerate) concentration
b. decreased pH
c. decreased CO2
d. decreased temperature
?
- If the total pressure of a mixture of gases is 740 mmHg and its composition is 20% oxygen, 0.04% carbon dioxide, 75% nitrogen and 5% water vapour, then the partial pressure of oxygen would be
a. 20 mmHg
b. 148 mmHg
c. 152 mmHg d. 720 mmHg
b. 148 mmHg
O2 = 20% of 740 = 148mmHg
- The bacteria found in a culture of sputum from a patient with tuberculosis are most likely to be
a. Haemophilus influenzae b. Mycobacterium tuberculosis c. Mycoplasma pneumonia d. Pseudomonas aeruginosa
?
- Lower respiratory tract infections
a. are uncommon and minor b. do not include bronchitis c. include pneumonia d. occur approximately 2-4 times per year
?
indicate the ONE INCORRECT option
- Activation of postganglionic sympathetic fibres results in
a. decreased heart rate
b. increased blood flow to skeletal muscle
c. increased sweat secretion d. reduced circulation to the skin
a. decreased heart rate
2.Sympathetic:
i) Symapthetic:
Preganglionic fibre -> ganglion
-> releases acetylcholine (ACh)
-> activates nicotinic (N2) receptor
-> action potential moves along postganglionic fibre
-> releases norepinephrine (NA)
-> activates (alpha/beta) adrenergic receptor.
ii) Adrenal medulla:
Preganglionic fibre -> adrenal medulla
-> releases acetylcholine (ACh)
-> stimulates nicotinic receptor of chromaffin cell
-> makes epinephrine
-> moves along postganglionic fibre
-> releases epinephrine
->sent into circulatory system
-> stimulates adrenergic receptors of heart
-> incr. heart rate.
The sympathetic nervous system’s primary process is to stimulate the body’s fight-flight-or-freeze response. It is, however, constantly active at a basic level to maintain homeostasis homeodynamics.
Can accelerate heart rate; widen bronchial passages; decrease motility of the large intestine; constrict blood vessels; increase peristalsis in the oesophagus; cause pupillary dilation. perspiration and raise blood pressure.
indicate the ONE INCORRECT option
The adrenal medulla
a. contains chromaffin cells
b. is innervated by the sympathetic nervous system
c. possesses nicotinic receptors
d. secretes acetylcholine into the circulation
d. secretes acetylcholine into the circulation
ii) Adrenal medulla: Preganglionic fibre -> adrenal medulla -> releases acetylcholine (ACh) -> stimulates N2 (nicotinic) receptor of chromaffin cell -> makes epinephrine -> moves along postganglionic fibre -> releases epinephrine ->sent into circulatory system -> stimulates adrenergic receptors of heart -> incr. heart rate.
It is the innermost part of the adrenal gland, consisting of cells that secrete epinephrine (adrenaline), norepinephrine (noradrenaline), and a small amount of dopamine in response to stimulation by sympathetic preganglionic neurons.
indicate the ONE INCORRECT option
- Epithelial tissues
a. are able to regenerate
b. are vascular
c. consist of one or more layers of cells, plus a basement membrane
d. cover surfaces and line cavities and tubes
b. are vascular
- Epithelia:
- Covers inner & outer surfaces
- Line cavities & tubes eg. Hollow organs, airways, blood vessels
- Glands
Characteristics:
Attachment
Avascularity -> no blood vessels run through it
Regenerates
Polarity (apical -> faces surface & basal -> bottom)
Closely packed cells supported by basement mem
Classification based on no of cells and shape in most superficial layer - No. of cell layers:
> Simple -> one layer
> Stratified -> more than one layer - Shape:
> Squamous (flat)
> Cuboidal (cube)
> Columnar (rectangle)
Examples of epithelial tissue:
- Simple squamous
Exchange of nutrients & gases -> Blood vessels & alveoli
- Non-keratinised stratified squamous
Protection -> Oral cavity & oesophagus
- Keratinised stratified Squamous
Waterproof protection/barrier -> Skin
- Simple cuboidal epithelium
Secretion & absorption -> Glands & kidney tubules
- Simple columnar epithelium
Absorption & secretion -> Gastrointestinal tract
–> also have microvilli -> Enabling absorption of nutrients.
- Pseudostratified ciliated columnar epithelium with goblet cells
Mucociliary escalator -> produce mucous -> particles inhaled -> trapped in mucous.
-> Cilia moves mucous upwards to back of throat for swallowing.
-> Trachea & large respiratory airways.
-> Also has cilia & goblet cells.
Trachea appears stratified -> some cells don’t reach free surface -> All touch
basement mem.
indicate the ONE INCORRECT option
- Simple squamous epithelium can be found lining the
a. alveoli
b. arteries
c. bronchioles
d. heart
c. bronchioles
Examples of epithelial tissue:
- Simple squamous
Exchange of nutrients & gases -> Blood vessels & alveoli
- Non-keratinised stratified squamous
Protection -> Oral cavity & oesophagus
- Keratinised stratified Squamous
Waterproof protection/barrier -> Skin
- Simple cuboidal epithelium
Secretion & absorption -> Glands & kidney tubules
- Simple columnar epithelium
Absorption & secretion -> Gastrointestinal tract
–> also have microvilli -> Enabling absorption of nutrients.
- Pseudostratified ciliated columnar epithelium with goblet cells
Mucociliary escalator -> produce mucous -> particles inhaled -> trapped in mucous.
-> Cilia moves mucous upwards to back of throat for swallowing.
-> Trachea & large respiratory airways.
-> Also has cilia & goblet cells.
Trachea appears stratified -> some cells don’t reach free surface -> All touch
basement mem.
Both the endothelial lining of blood vessels and the mesothelial lining of the body cavities are simple squamous epithelium.
Bronchiole walls consist of ciliated cuboidal epithelium and a layer of smooth muscle.
Line several body cavities including the pleural cavity housing the lungs, peritoneum (abdominal cavity containing the stomach and intestines) and the mediastinum (part of the thoracic cavity that contains the heart, lungs, trachea and esophagus). These tissues are also called the endothelium when they form the inner lining of blood and lymph vessels
• Fibrous Pericardium: Characteristics: - Inelastic sac -> dense tissue - Inferior fusion -> diaphragm - Superior infusion -> large vessels Function: - Prevents overfilling of heart - Anchors position
• Serous pericardium: Characteristics: - Double-layered serous membrane - Lies -> deep within -> fibrous pericardium - Contains: 1. Parietal pericardium: Lines inner surface -> fibrous pericardium 2. Visceral pericardium: Tightly adhered -> surface of heart 3. Pericardial cavity: Space between parietal & visceral layers Contains tissue fluid. Function: Prevents friction.
• Heart wall: - 3 layers: i) Endocardium: Inner layer -> Endothelium ii) Myocardium: Middle layer -> Cardiac muscle iii) Epicardium: Outer layer -> Visceral pericardium
indicate the ONE INCORRECT option
- The anatomical position refers to the body position when a person is stood with the
a. arms adjacent to the sides of the body
b. eyes directed anteriorly
c. lower limbs together with feet parallel
d. palms facing posteriorly
d. palms facing posteriorly
• Anatomical position:
Position of the upright body -> arms at sides -> palms facing forwards.
- Anterior (Ventral):
Front / Underside - Posterior (Dorsal)
Behind/ Upperside/back - Superior
Towards the head - Inferior
Towards the feet - Medial
The core/centre - Lateral
Towards the side/ away from core/centre - Proximal
Closer towards the trunk - Distal
Further from the trunk - Coronal/frontal plane:
Divides into front & back planes -> Anterior/ventral & posterior/dorsal - Horizontal/transverse plane
Divides into top & bottom planes -> Above & below waist -> Superior & Inferior - Midsagittal plane
Divides into right & left halves -> medial & lateral
indicate the ONE INCORRECT option
- Arteries found in the lower limb include the
a. anterior tibial
b. femoral
c. popliteal
d. ulnar
• Major arteries:
d. ulnar
- Arm: Axillary -> Shoulder Brachial -> Upper arm Radial -> Lateral Ulnar -> Medial - Leg: External iliac -> Hip area Femoral -> Upper leg Popliteal -> Back of knee Anterior tibial - Core: Right common carotid -> Right -> neck Left common carotid -> Left -> neck Brachiocephalic trunk -> Lungs Right subclavian -> Right -> under collarbone Left subclavian -> Left -> under collarbone Aortic arch -> Main part of heart Descending thoracic aorta -> Down inside lower end of rib cage -> spine Abdominal aorta -> Abdominal -> inside spine Common iliac -> Top of hip External iliac -> Lower hip -> top of leg Internal iliac -> Backbone
indicate the ONE INCORRECT option
- Blood rich in oxygen is found in the
a. brachial arteries
b. common carotid arteries
c. pulmonary arteries
d. subclavian arteries
c. pulmonary arteries
• Major arteries:
Pulmonary artery: carrying blood from the right ventricle of the heart to the lungs for oxygenation.
the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch.
- Arm: Axillary -> Shoulder Brachial -> Upper arm Radial -> Lateral Ulnar -> Medial - Leg: External iliac -> Hip area Femoral -> Upper leg Popliteal -> Back of knee Anterior tibial - Core: Right common carotid -> Right -> neck Left common carotid -> Left -> neck Brachiocephalic trunk -> Lungs Right subclavian -> Right -> under collarbone Left subclavian -> Left -> under collarbone Aortic arch -> Main part of heart Descending thoracic aorta -> Down inside lower end of rib cage -> spine Abdominal aorta -> Abdominal -> inside spine Common iliac -> Top of hip External iliac -> Lower hip -> top of leg Internal iliac -> Backbone
indicate the ONE INCORRECT option
- The constituents of plasma include
a. albumin
b. fibrinogen
c. globulin
d. haemoglobin
d. haemoglobin
haemoglobin found in RBCs, not plasma
• Composition of blood:
- Plasma: 55%
Water -> 92%
Plasma proteins -> 7%
-->Albumin, Globulin, Fibrinogen, regulatory proteins
Other solutes -> 1%
-->Electrolytes, organic nutrients, waste.
- Red Blood Cells: 45%
- White Blood cells: <1%
- Platelets: <1%
indicate the ONE INCORRECT option
- The white blood cells known as ‘granulocytes’ include
a. basophils
b. eosinophils
c. Lymphocytes
d. neutrophils
c. Lymphocytes
• White blood cells: Also known -> Leukocytes Nucleated Act mainly outside tissues In-transit -> sites of activity Can migrate out of bloodstream -> extravastation (diapedesis) Capable -> amoebid movement Attracted -> specific chemical stimuli 2 groups: i) Granulocytes - Neutrophils - Eosinophils - Basophils ii) Agranulocytes - Lymphocytes - Monocytes Neutrophils, eosinophils & monocytes -> phagocytosis Functions: - Defence -> pathogens - Toxin & waste removal - Removal -> damaged cells
indicate the ONE INCORRECT option
- Platelets
a. are 2-3µm in diameter
b. are regulated by thrombopoietin (TPO)
c. do not contain granules
d. have a lifespan of 7-10 days
c. do not contain granules
• Platelets:
- Structure:
Small
Oval
No nucleus
2-3 micrometres diameter
Contain granules
- Functions:
Megakaryocyte cytosplasm
Production controlled by
>>No. circulating platelets -> negative feedback
>>Thrombopoietin (TPO) release -> incr. platelet no.s
Lifepsan 7-10 days
Variety functions -> essential -> haemostasis
indicate the ONE INCORRECT option
- Return of blood to the right atrium (venous return)
a. can be aided by contraction of skeletal muscles in the leg
b. can be aided by normal breathing movements
c. normally rises when a person suddenly stands up
d. is affected by venomotor tone
• Factors Influencing c. normally rises when a person suddenly stands up
Venous Return / Central Venous Pressure:
1. Posture:
- Blood volume influenced by gravity -> posture.
- Standing venous pooling in legs
»Decr. venous return.
2. Muscle pump:
- Venomotor tone involving constriction -> veins -> skeletal muscles.
- Venous return facilitated -> valves
»Prevent backflow of blood
3. Respiratory Pump:
- Inspiration creates internal pressure difference by lowering intra-thoracic pressure & incr. intra-abdominal pressure.
indicate the ONE INCORRECT option
- The extrinsic control of blood vessel tone is mediated by
a. angiotensin II
b. diuretic hormones
c. physical stress/trauma
d. the sympathetic nervous system
c. physical stress/trauma ?
-> See below -> processes
-> Physical stress/ trauma & angiotensin not a process/ internal regulation it is likely a cause but not a mediator.
Physical stress/trauma cannot be regulated by body, angiotensin II can
-> Angiotensin -> Autoregulatory nervou system
-> Diurtetic hormones -> long term control
-> P
• Blood vessel tone controlled -> interrelated processes
Automatic / intrinsic
Short term
Long term
Control measures.
• Response & Regulation of Blood Pressure:
Homeostasis:
- Altered Blood pressure / volume
Physical stress
Eg. Trauma, high temp, etc.
Chemical changes
Eg. Decr. O2 / decr. pH / Incr. CO2 / Incr. vasodilatory metabolites
Increases tissue activity / Intrinsic Control
- Inadequate blood pressure & flow
»Autoregulation:
Decr. resistance & incr. blood flow
> Homeostasis returned.
- Insufficient Autoregulation:
Stimulates receptors -> sensitive to systemic changes -> blood pressure /
Chemistry.
Activates cardiovascular centres -> Central Nervous System
Elevates Blood pressure -> Short Term
»_space;Stimulation -> heart rate & peripheral vasoconstriction
–» Sensory Nervous System.
Return -> Homeostasis.
indicate the ONE INCORRECT option
- In the coronary circulation
a. blood flow through the arteries is greatest during ventricular systole
b. blood flow will increase during a period of exercise
c. extraction of oxygen at the capillaries is greater than in most other tissues
d. partial blockage of an artery may cause angina
c. extraction of oxygen at the capillaries is greater than in most other tissues ?
- > elimination?
• Haemodynamics:
Anything that makes the coronary supply routes restricted can build danger of angina
-> Pressure at ventricular systole highest as blood forced out of ventricles at high pressure.
Blood flow determined:
- Resistance -> R
- Pressure difference -> P
F = ▲P / ▲R
Determined by:
->> L = length of vessel
->> r = radius of vessel
->> ꞃ = fluid viscosity
>>(protein conc.)
• Afterload:
Pressure opposing ejection of blood from heart
Influenced -> Blood vessel tone -> Vasoconstriction/dilation
Major effect -> cardiac output.
• Blood Pressure = Cardiac Output x Total Peripheral Resistance
Cardiac Output -> ▲HR & SV
• Response & Regulation of Blood Pressure:
Homeostasis:
- Altered Blood pressure / volume
Physical stress
Eg. Trauma, high temp, etc.
Chemical changes
Eg. Decr. O2 / decr. pH / Incr. CO2 / Incr. vasodilatory metabolites
Increases tissue activity / Intrinsic Control
- Inadequate blood pressure & flow
»Autoregulation:
Decr. resistance & incr. blood flow
> Homeostasis returned.
- Insufficient Autoregulation:
Stimulates receptors -> sensitive to systemic changes -> blood pressure /
Chemistry.
Activates cardiovascular centres -> Central Nervous System
Elevates Blood pressure -> Short Term
»_space;Stimulation -> heart rate & peripheral vasoconstriction
–» Sensory Nervous System.
Return -> Homeostasis.
indicate the ONE INCORRECT option
- The bicuspid (mitral) valve
a. closes as a result of contraction of the papillary muscles
b. is open during most of ventricular diastole
c. lies between the left atrium and the left ventricle
d. makes a noise, as it closes, that forms part of the first heart sound
a. closes as a result of contraction of the papillary muscles
–> Remains closed from previous ventricular contraction & is only opened again by pressure changes during systole.
The sound of a heartbeat is caused by the heart valves opening and closing as they pump blood.
The papillary muscles attach to the cusps of the atrioventricular valves via the chordae tendineae and contract to prevent inversion or prolapse of these valves on systole
• Heart Valves:
Prevent backflow of blood
Atrioventricular:
- Tricuspid (Right AV) valve
- Bicuspid/mitral (Left AV) valve
Between atria & ventricles
Open -> blood flow -> atria to ventricles
Anchored -> Chordae tendinae to papillary muscles.
When ventricular pressure < atrial pressure
Valve opens -> loose chordae tendinae
When ventricular pressure > atrial pressure
Valve begins to close -> pulls chordae tendinae -> papillary muscle contracts -> prevents inversion of valve -> backflow of blood.
Semilunar: - Pulmonary - Aortic Guard entrances -> aorta & pulmonary trunk Open -> force of blood -> contraction of ventricles Bloodflow -> backwards -> aorta & pulmonary trunk -> ventricular relaxation Accumulates in cusps -> shut. Prevent backflow of blood -> ventricles.
indicate the ONE INCORRECT option
- The reflex responses to an increase in mean arterial blood pressure may include a decrease in
a. cardiac output
b. heart rate
c. parasympathetic nerve activity
d. total peripheral resistance
Baroreceptors & Control -> Blood Flow:
c. parasympathetic nerve activity
• Inadequate Blood supply / Decr. Blood Pressure:
- Inhibition -> baroreceptors
Activation
Cardioacceloratory Centre
Vasomotor Centres
Inhibition
Cardioinhibitory Centre
>> Incr. Cardiac Output & Heart Rate
- Vasoconsriction
• Rise -> Blood Pressure:
- Stimulation -> Baroreceptors
Activation
Cardioinhibitory Centre
Inhibition
Cardioacceloratory Centre
Vasomotor Centres
>> Decr. Cardiac Output & Heart Rate
- Vasodilation.
-> Vasodilation -> Incr. diameter of vessels -> decr. resistance -> decr. pressure
• Blood Pressure = Cardiac Output x Total Peripheral Resistance
Cardiac Output -> ▲HR & SV
Total Peripheral Resistance -> ▲Arteriolar Radius
- Parasympathetic more active -> vegetative (passive/calm) situations.
Parasympathetic controls when in relaxed state -> decr. activity of active mecahnisms controlled by sympathetic
Therefore would decr. increases in heart rate
indicate the ONE INCORRECT option
- Hypertension can be treated with
a. ACE-activators
b. beta-blockers
c. calcium channel antagonists
d. diuretics
• Hypertension: Affects nearly one billion One of the main causes -> premature death. Nearly 8 million fatalities per year a. ACE-activators
Types: - Primary Hypertension (Essential / Idiopathic) Unknown medical cause Links: Genetic predisposition Alcohol consumption Obesity Lack of excersise Diabetes Intrauterine environment - Secondary Hypertension Known medical cause 1) Kidney Disease: Incr. Angiotensin II >> Vasoconstriction & expansion -> cellular fluid 2) General endocrine disorders Eg. Diabetes, Cushing’s 3) Adrenal medulla disease (Phaeochroocytoma) Excessive adrenaline secretion Treatment: - Inhibit angiotensin II production -> inhibit Angiotensin-Converting-Enzyme (ACE) >> Prevents renal absorption -> Na+/H2O
> Prevents incr. blood volume
- Ibhibition -> Angiotensin II induced vasoconstriction -> Angiotensin II receptor
blocker.
>> Inhibitd membrane cardiac / vascular depolarizoation
> Decr. CO -> vasodilation.
- Calcium-channel blocker / thiazide diuretic
>> Incr. loss -> Na+ & H2O
> Decreases fluid volume, venous return & cardiac output.
- Reduce TBR -> inhibition -> noradrenaline action.
- Alpha-adrenoreceptor Antagonists (alpha-Blockers)
Reduce TBR -> inhibition -> noradrenaline action.
- Beta-adrenoreceptor Antagonists (beta-Blockers)
Decr. CO2,
Decr. central activity -> Symapthetic nervous system
Decr. release -> Renin
->> Favourable secondary actions Risks: - Atherosclerosis - Stroke / Cerebrovascular Accident - Heart Failure - Renal Failure - Aneurysms
indicate the ONE INCORRECT option
- Structures located in the conducting portion of the respiratory tract include the
a. larynx
b. respiratory bronchioles
c. terminal bronchioles
d. tertiary bronchi
• Respiratory tract organised according to function:
b. respiratory bronchioles
- Conductive: Filteration, warming & moistening air Conducting air into lungs Structures: Nasal cavity & paranasal sinuses Pharynx Larynx Trachea Primary bronchi Secondary bronchi Tertiary Bronchi Bronchioles Terminal Bronchioles - Respiratory: Sites of gas exchange Structures: Respiratory Bronchioles Alveolar Ducts Alveolar Sacs Alveoli
indicate the ONE INCORRECT option
- Openings in the diaphragm transmit the
a. abdominal aorta
b. inferior vena cava
c. oesophagus
d. trachea
?
indicate the ONE INCORRECT option
- Movement of air into the lungs is aided by
a. a decrease in intrathoracic pressure
b. an increase in the transverse diameter of the thorax
c. an increase in the vertical diameter of the thorax
d. relaxation of the diaphragm
d. relaxation of the diaphragm
• Incr. Thoracic Volume:
• Ventilation:
- Atmospheric pressure > Intrapulmonary / Intraalveolar pressure
Air enters lungs
- Intrapulmonary / intraalveolar pressure > atmospheric pressure
Air expelled from lungs
- Change -> volume = change -> pressure
- Atmospheric pressure = 760mmHg
• Incr. Thoracic Volume:
- Incr. Vertical diameter
- -> Incr. thoracic volume incr. movement of air to lungs
Contraction of diaphragm incr. vertical diameter
Responsible for 75% incr. thoracic capacity
- Incr. Anterior Posterior diameter
Elevation of ribs incr. Anterior Posterior diameter
-> (Joint with Transverse Diameter)
Responsible for 25% thoracic capacity.
Elevation of ribs -> external end -> makes them more horizontal & pushes sternum forward (pump handle movement)
Incr. AP diameter
- Incr. transverse diameter
Elevation of ribs incr. transverse diameter
-> (Joint with Transverse Diameter)
Responsible for 25% thoracic capacity.
Many of the ribs
Lowest near their middle
Rise at each end
Eg. Bucket handle
Rise of middle of rib -> movement away from midline of body
Transversally widens chest (Left -> Right)
• Inspiration:
- Active process
- At rest:
Diaphragm (75%)
External intercostal muscles (25%)
Contracted diaphragm flattens
-> Vertical diameter of thorax increased.
External intercostals elevate ribs -> incr. Anterior Posterior & Transverse
diameters.
- Forced:
Pectoralis major
Pectoralis minor
Scalenes
Serratus anterior
Sternocleidomastoid
Assist -> rib elevation
-> Incr. speed & amount of movement
indicate the ONE INCORRECT option
- Surfactant
a. decreases surface tension
b. increases lung compliance
c. is more concentrated in smaller alveoli
d. makes smaller alveoli more difficult to inflate
Pulmonary surfactant are formed by type II alveolar cells
Greatly reduce surface tension, increasing compliance allowing the lung to inflate much more easily, reducing the work of breathing. It reduces the pressure difference needed to allow the lung to inflate.
As the alveoli increase in size, the surfactant becomes more spread out over the surface of the liquid. This increases surface tension effectively slowing the rate of expansion of the alveoli. Hence Surfactant reduces surface tension more readily when the alveoli are smaller because the surfactant is more concentrated.
indicate the ONE INCORRECT option
Gas exchange occurs through diffusion and is dependent upon
a. a short diffusion distance b. a small surface area
c. the concentration gradient between alveolar air and blood
d. the solubility of gases
? -> small surface area decr. rate of diff but still has an effect on g.e. Q isn’t specific on whther dpendency is negative or positive so is this incorrect or not??
Henry’s law states that the concentration of gas in a liquid is directly proportional to the solubility and partial pressure of that gas. The greater the partial pressure of the gas, the greater the number of gas molecules that will dissolve in the liquid. The concentration of the gas in a liquid is also dependent on the solubility of the gas in the liquid.
Ventilation causes partial pressures of oxygen and carbon dioxide change, affecting the diffusion process that moves these materials across the membrane. This will cause oxygen to enter and carbon dioxide to leave the blood more quickly.
-> Short diffusion distance -> faster diffusion
Higher conc. gradient -> faster diffusion
-> small surface area -> decr. rate of diffusion
indicate the ONE INCORRECT option
- In the control of breathing, central chemoreceptors
a. are present in the medulla
b. respond to a change in pH
c. respond to hypercapnia
d. respond to hypoxia
d. respond to hypoxia
• Neural Control of Ventilation:
- Chemoreceptors detect changes in PO2, PCO2 & pH
-> Send impulses / signals
Vagus (CN X) & Glossopharyngeal (CN IX) nerves
(Afferent pathway)
- Impulses transported -> Vagus (CN X) & Glossopharyngeal (CN IX) nerves
Respiratory Centres of Brain Stem
- Respiratory Centres of Brain stem
-> Send impulses / signals
Phrenic, intercostal & other nerves
(Efferent pathway)
- Impulses transported -> Phrenic, intercostal & other nerves
Muscles in ventilation
• Central Chemoreceptors:
- Located -> Medulla oblongata of brainstem
- Respond to changes in PCO2 & pH
Hypercapnia, also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood.
Hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level
• Peripheral Chemoreceptors: - Detect changes -> PO2, PCO2 & pH - Aortic Bodies Located -> Aortic Arch Innervated -> Vagus (CN X) - Carotid Body Located -> Common Carotid Artery Innervated -> Glossopharyngeal (CN IX)
• Respiratory Centres:
- Group of neurons -> Brain stem
- Send impulses to muscles of ventilation
- Medullary Rhythmicity Area
Dorsal Respiratory Group (DRG)
Sets rhythm, stimulates muscles of quiet inspiration
Ventral Respiratory Group (VRG)
Involved in forced inspiration & expiration
- Pneumotaxic area (Pons)
Influences DRG by regulating duration of inspiration.
indicate the ONE INCORRECT option
- Symptoms of asthma include
a. bronchoconstriction
b. mucus secretion
c. oedema of airway mucosa
d. reduced surfactant secretion in lungs
?
indicate the ONE INCORRECT option
- Emphysema leads to
a. hyperventilation b. increased residual volume c. shortness of breath on exertion d. under-inflated lungs
?
