Body Systems Flashcards
Homeostasis
Regulation of a constant internal environment
Anastomosis
Connection between two passages (e.g. blood vessels) that are normally diverging
Bifurcates
Division of blood vessel into two branches
Endocardium
Inner layer of heart
SImple squamous, endothelium, with a small lamina propria
Myocardium
Middle layer of heart
Cardiac muscle
Epicardium
Outer layer of heart
Visceral pericardium
Lamina propria
Thin layer of loose areolar connective tissue, lying below epithelium.
Aurcile
Extension of main heart chamber, on the top of the atria.
Haemostasis
The stopping of blood flow, first stage of wound healing
Haemotapoiesis
Production of all cells
Red and white blood cells and platelets
Percentage composition of blood
55% plasma
45% formed elements
Erythropoieten
Hormone required for for red blood cell production
Blast cell
Premature cell, may remain in bone marrow
Anaemia
Haemoglobin concentration in whole blood below accepted normal range
Causes of anaemia
- Decreased RBC prod.
- INcreased RBC dest.
- Blood loss
Extravasation
Leakage of blood or lymph out of blood vessels into surrounding tissue.
Diapedesis
Passage of blood cells through capillary walls
Difference between leukocyte and lymphocyte
Lymphocyte - type of WBC
Leukocyte - all WBCs
Platelet growth factor
Thrombopoietin
Red blood cell growth factor
Erythropoietin
Mean arterial pressure =
Mean arterial pressure = diastolic pressure / 1/3 of pulse pressure
Pulse pressure
Difference in systolic and diastolic pressures
Considerations of cardiac cycle
- Electrical events
- Mechanical events
- Electro-mechanical contraction coupling
ECG
Detects electrical responses across the heart, shows action potentials occurring across heart.
What stages of the cardiac cycle does the ECG reflect?
- atrial contraction / relaxation;
- ventricular contraction / relaxation;
- conduction velocities of the electrical signals
QT interval
Time from initiation of ventricular contraction to end of ventricular relaxation
T wave
Ventricle depolarization and relaxation
QRS complex
Spread of electrical signal causing ventricular myocyte depolarization and contraction
Tachycardia
Overly fast heart rate
Bradycardia
Overly slow heart rate
Positive inotropic effect
Increased contractility of the heart caused by a molecule
Hypotension
When blood pressure is too low
Hypertension
When blood pressure is too high - leads to CHD
Cardiac output
stroke volume x heart rate
total peripheral resistance
sum of arteriolar resistance
Exception to mediators in blood vessel resistance
Pulmonary circulation -
Low O2 and High CO2 cause constriction of arterioles
Capillary exchange
Chemical and gaseous exchange between blood and interstitial fluid across capillaries.
Fenestrated capillaries
Present in hypothalamus, kidneys, endocrine organs and intestinal tract
Voltage-gated Ca2+ Channel Antagonists
Inhibit membrane cardiac/vascular depolarization:-
↓ CO; cause vasodilation
Angiotensin II Receptor Antagonists
Blocks actions of AT2 on vasoconstriction
ACE inhibitors
- Inhibit actions of AT2 on aldosterone prod. so preventing renal Na+/H2O absorption & blood vol. increase
- Inhibits vasoconstrictor actions of AT2
Thiazide Diuretics
↑ Na+ & water loss, so decrease fluid volume
↓ venous return
↓ cardiac output (CO)
α-Adrenoceptor Antagonists “α-blockers”
Reduce TPR by inhibiting action of noradrenaline
β-Adrenoceptor Antagonists “β-blockers”
↓ CO
↓ SNS activity centrally
↓ renin release – leads to favoured secondary actions
Arteriosclerosis
Hardening and thickening of artery walls.
Loss of elasticity in tissue.
Atheroscleorosis
Plaque damage to the endothelium, atheroma in blood vessel walls.
Total body water
42 litres
Total intracellular fluid
25 litres
Total extracellular fluid
17 litres
comprises plasma, interstitial fluid and transcellular fluid
Transcellular fluid found
Have to cross over layer of epithelilal to get it. Generally excretions and secretions.
Difference between interstitial fluid and other transcellular fluids
No proteins
Types of carrier protein
Facilitator/uniport
Cotransporter/symport
Exchanger/antiport
Facilitator/uniport
Transport 1 type of ion in one direction
Symport/cotransporter
Transport 2 types of ion in one direction
Antiport/exchanger
Swaps ions
e.g. Cl- for K+
Which channel in a cell are all other ion channels dependent on?
Na+, K+ pump
Electric gradient of cell
negative inside relative to outside, due to K+.
What maintains electrical gradient of cell?
Negative organic ions attract K+ meaning it cannot leave cell. Present in excitable cells.
Oncotic/colloid osmotic pressure
Osmotic pressure exerted within cardiovascular system by proteins found in blood plasma.
Water distribution in blood vessels and capillary bed
Via capillary endothelium.
Hydrostatic pressure from heart contractions forces water out. Osmotic pressure from plasma proteins draws water in.
Innermost layer of intestinal epithelial cell, facing lumen
Apical membrane
Outermost layer of intestinal epithelial cell, facing cells and capillaries
basolateral
Negative feedback control
aims to maintain a controlled variable at its set point
What does the sensor send an impulse to in order to activate the effector to correct the change in a variable
Integrating centre
What centre of the brain controls blood pressure
medulla oblongata
Positive feed back
Initial stimulus causes a response which reinforces itself
Examples of positive feedback
1) Action potential in nerves - stops upon depolarisation
2) ovulation - stops when egg is released
3) blood clotting - stops once clot has formed
Thrombin
A hormone involved in the positive feedback response of blood clotting, by activating clotting factors which in turn, activate release of thrombin
What tissue does the autonomic nerves control
SMooth & cardiac muscle, glands
What tissue does somatic nerves control
skeletal muscles - voluntary
System of neurons in autonomic neurons
Preganglionic neuron
Postganglionic neuron
Target cell
Ganglionic neurotransitter in parasympathetic nervous system
Acetyl choline
Ganglionic neurotransmitter in sympathetic nervous system
Acetyl choline
Where is oxytocin released?
Posterior pituitary
Outflow from CNS sympathetic
Thoraic and lumbar
Outflow from CNS paraympathetic
Cranial and Sacral
Prepanglionic fibre sympathetic
short
Prepganglionic fibre parasympathetic
long
Postganglionic fibre sympathetic
long
Postganglionic fibre parasympathic
Short
Neuroeffector transmitter sympathetic
NA
Neuroeffector transmitter parasympathetic
ACh
Four types of tissue
Epithelial
Connective
Muscle
Nervous
Epithelial tissue
- Dense populations of connected cells, organised in varying layers and shapes
- Line surfaces of our body
- capable of regeneration
- Polarity (apical + basal)
Connective tissue
- Sparse populations of cells suspended in a uniform, extracellular matrix
- Matrix & function differing
- 6 types: loose, fibrous, adipose, cartilage, bone and blood.
Loose connective tissue
- Connects epithelial tissue to underlying tissue
- Holds internal organs in place
Fibrous connective tissue
- Connects muscle to bone
- Ligands
- Made of strong collagen fibres
Adipose connective tissue cells
- Fat storing cells
- Insulates body
- Energy stockpile
Cartilage connective tissue
- Rubber extracellular matrix
- Found at ear, nose & bones
- Shock absorber
- Reduces friction
Bone as a connective tissue
- Extracellular matrix consists of rubbery protein fibres hardened by Ca2+ salt deposits
- Provide support and protection as well as movement
Blood as a connective tissue
- Different cells in plasma
- Circulating fluid of cardiovascular system
- Gas exchange and chemical reactions
Muscle tissue
- Skeletal
- Cardiac
- Smooth
Skeletal muscle
- Striations due to organised contracting proteins
- Linear cylindrical cells
- Voluntary movement
- Bones and tendons
Cardiac muscle
- Striations
- Heartbeat
- Heart
Smooth muscle
- Involuntary muscle contractions
- Internal organs and blood vessels
Nervous tissue
- send & receive action potentials
- Electrical communication in body
Epithelial cell layers
Simple - one layer
Stratified - two+ layers
Shapes of epithelial cells
Squamous
Cuboidal
Columnar
Intercellular junction
Specialised area of cell membrane that binds cells together.
- Desmosomes
- Hemidesmosomes
- Tight junctions
- Gap junctions
Desmosomes
Intercellular junction
- Between adjacent cells
- Very strong connections
- Resist stretching and twisting
- Between stratified squamous cells in skin
Hemidesmosomes
Intercellular junction
- Anchor cells to basement membrane
Tight junctions
Intercellular junction
Apical side of cells, interlock proteins and membranes, preventing passage of water and solutes between cells.
Gap junction
Allows small molecules and ions to pass through cells allowing spread of impulses
Loose (areolar) connective tissue
- Just below epithelium
- Contains ground substance and few fibres
- Variety of cells
Similarities between muscle tissue types
- muscle fibres, contract parallel to length
- Numerous mitochondria
- Contractile elements
Avascular
appears stratified as some cells don’t reach free surface.
Pseudostratified
appears stratified as some cells don’t reach free surface
Mucociliary escalator
defence mechanism protecting the lungs involving ciliary action & flow of mucus from the bronchioles
3 layers of blood vessels
Tunica intima
Tunica media
Tunica adventitia
Tunica intima
- Simple squamous epithelium
- Basal lamina of epithelial cells
Tunica media
- Smooth muscle fibres in connective tissue
- May have elastic fibres
Tunica adventia
- Connective tissue
- Merges with surrounding connective tissue
- Large vessels/veins
Types of arteries
- Elastic/conducting
- Muscular
- Arterioles
Elastic arterioles
e. g. aorta, common carotid
- withstands changes in presssure
- Ensures continuous blood flow
Muscular arteries
e. g. brachial, femoral
- Name = area going to
- Distribute blood to muscles and organs
- Vasodilation/constriction to control rate of blood flow
Arterioles/resistance vessels
- Vasoconstriction/dilation
- Control blood flow to organs
Types of capillaires
Continous
Fenestrated
Sinusoidal
Continous capillaries
Pass through cells
e.g. smoothmuscle, lungs
Fenestrated capilarries
- Pores in endothelial lining
- Rapid exchange of water and large solutes
- Absorption
Sinusoidal capillaries
- Between endothelial cells are spaces - no basement membrane
- Exchange of large solutes
- Blood moves through slowly
Meta arterioles
Supply single single capillary bed
Precapillary sphincter
- guarded entrance to each capillary
- Increase/decrease blood flow
Arteriovenous anastomoses
- Direct communication between arteriole and veunule
- When dilated blood bypasses capillary bed
Veins
Low pressure system
Easily distensible
Superior/inferior
Higher/lower
Proximal/distal
Closer to/further away
Medial
Towards mid line
Anterior/ventral
Posterior/dorsal
Back and front
Sagittal
Splits body from right to left
Coronal/frontal
Side to side, front and back
Transverse/horizontal
Upper and lower parts
Blood circulatory system contains
- Systematic
- Pulmonary
- Coronary
Specialised circulatory systems
- portal
- foetal
Jugular
Neck
Brachium
Arm
Popliteal fossa
Back of knee
Auxillary fossa
Arm pit
Ilium
Hip bone
Febur
Thigh
TIbia
Bone in lower leg
Radius and ulna
Forearm
Systematic circulation
- High pressure system on arterial side
- Takes and returns blood from heart to tissues
Braciocephalic trunk
- Vessel leaving aortic arch
- Arm and head
- Breaks into common carotid and right subclavian
Subclavian artery leads to
Auxillary
Brachial
forearm
radial and ulna
External illiac extends to
lower limbs
femoral
politeal
anterior and interior tibial
Venous return of blood in legs
Anterior/interior tibial Popliteal Femoral External and internal iliac Common iliac Inferior vena cava
Venous return in upper limbs
Radial and ulna Brachial Subclavian Brachiocephalic Superior vena cava
Portal crculation
Involves two capillary beds on either side of a portal vessel.
Hepatic portal goes from intestines to liver, where nutrients are removed.
Foetal circulation
Bypasses liver, lungs and GI tract
Lymphatic tissues and organs
Thymus, spleen, lymph nodes
Functions of lymphatic system
Body defense
Drainage of interstitial fluid
Lymphatic drainage
Lymph capillaries ->Vessels -> trunks
Filters through nodes
Drains into thoraic duct (L. Subclavian) or right lymphatic duct (R. subclavian)
Pericardium
Layers of tissue covering and protecting the heart.
Serious pericardium
Double layered serous membrane that lies deep to fibrous pericardium.
- outer and inner layer
Fibrous pericardium
Dense, connective, elastic tissue.
Prevents heart from overfilling and anchors its positions
3 layers of heart wall
Endocardium
Myocardium
Epicardium
Endocardium
inner layer of heart – simple squamous, endothelium with small lamina propria
Myocardium
middle layer of heart – cardiac muscle
Epicardium
outer layer of heart – visceral pericardium.
- Connective tissue w/ serous membrane
- Coronary vessels run through it
Semilunar valves
Pulmonary
aortic
Atrioventricular valves
Tricuspid - R
Bicuspid - L
Anchored by chordae tendinae to papillary muscles
Angiotherapy
Medical imaging technique used to examine patency of vessels
Electrocardiogram
Records electrical activity of the heart
Lamina propria
Thin layer of loose areolar connective tissue, lying below epithelium. Constitutes mucosa w/ epithelium & basement membrane.
Chordae tendineae
Group of tough, tendinous strands in heart. Important in holding AV valves in place whilst heart pumps blood
Trabeculae carnae
Meaty ridges which project from inner surface of right ventricle of heart.
Papillary muscles
muscles in ventricles of heart, attach to cusps of AV valves
Pectinate muscles
parallel ridges in walls of atria of heart. Resemble teeth of a comb.
Anastomosis
Interconnection between parts of a branching system forming a network
3 circulatory shortcuts in foetus
- Ductus venosus
- Foramen ovale
- Ductus arteriosus
Ductus venosus
connects umbilical vein to inferior vena cava (bypasses liver)
Becomes ligamentum venosum after birth
Foramen ovale
Connects right & left atria
Becomes fossa ovalis after birth
Ductus arteriosus
connects pulmonary trunk to arch of aorta
Becomes ligamentum arteriosum after birth
P wave
Atrial depolarization and contraction
QRS complex
Spread of electrical signal causing ventricular muscle contraction, and arterial relaxation
T wave
Ventricle repolarised and relaxed
QT interval
Time from ventricle contraction to relaxation
