Book 1 Flashcards
What are the functions of the 3 main structures of the brain??
Cerebrum - higher function skills, like speech, higher intellectual function and fine control of movement
Cerebellum- balance and co ordination
Brain stem- autonomic processes, control of bp, blood volume, heart rate, respiration, arousal
What two hemispheres are the cerebrum divided into?? How do they communicate?
What 4 lobes are there of the cerebral cortex??
Left cerebral hemisphere and right cerebral hemisphere, communicate via corpus callosum
Temporal- speech, lanugae, hearing, smell
Occipital- passt visual experience and vision
Parietal - sensory
Frontal- motor, emotions, personality
What is the cerebral cortex for??
Concious thought and perception
Outermost 20mm of cerebral hemispheres
What is the sensory and motor cortex?
Sensory - parietal lobe. Sensory neurons from sensory organs like ears, eyes, arrive at sensory cortex
Motor - in frontal lobe responsible for planning, control and voluntary movement. gets info from cerebellum. And messages sent via motor neurons to initiate voluntary movement
What are the 3 parts of the brain stem and their functions?
Midbrain - upper part containing auditory and visual reflex centres, and contains cranial reflect activities like blinking and ducking head
Pons- middle part relays info between cerebrum and cerebellum. Helps coordinate breathing with medulla oblongata
Medulla oblongata - respiratory, vasomotor centre and cardiac centre for controlling breathing and cardiovascular system, also reflex systems like vomiting and swalloing
What are the meninges, blood brain barrier and cerebrospinal fluid csf
Meninges- membranes around cns for protection. Outter dura mater- strong thick. Arachnoid mater- transparent thin pia mater - delicate inner layer
Blood brain barrier - tight junctions between capillaries and astrocytes . Foot processes which encircle capillaries and create semi permeable layer separating blood from neurones in brain.
Cerebrospinal fluid- fluid made from ependymal cells in canal of spinal cord. Transparent fluid containing urea, protein, glucose, lactic acid. Contributes to intra cranial pressure, supports the weight of cranium, allows exchange of substances by medium, keeps structures moist, protection
What organ systems involved in intake of nutrients, oxygen and removal lf waste products
Oxygen- muscular system, nervous system and respiratory system
Nuritients - digestive system, muscular, endocrine, nervous
Removal of waste products - renal, urinary, respiratory system
Functions of cell membrane?!
Encloses cell contents Barrier Communication Cell movement Chemical reactions Celluar identity
Two types of endocytosis
Phagocytosis
Pinocytosis - cell drinking, vesicles allow small droplets inside the cell
How do hormones produce changes in target cells?
Changes in permeability of cell membrane, activation or deactivation of enzymes, stimulation of cell division, stimulation of synthesis of proteins or regulatory molecules
What 3 ways are endocrine cells, tissues and organs controlles
Neural, ions and hormonal (pituitary gland or hypothalamus)
Definition of homeostatis ?
Keeping the levels of interal environment eithin narrow defined limits regardless of what enters the body or how the external environment differs, by autocorrective self adjusting mechanisms.
Comtrolloed by neural and hormonal systems
Negative feedback reverses any shift away from optimum state, automatic response involving a corrective mechanism,
Effects of the sympathetic nervous system, part of the autonomic nervous system in PNS
Pupils dilate, promotes ejaculation, bronchi relax, increased breathing rate, rate increases in heart, noadrenaline adrenaline produced. Gi tract inhibited.
Skeletal muscle vaso dilation
Example of the antagonisitic relationship of para and sympathetic responses?
How does this effect meds to give
The heart
Para - neurones release chemical acetyl choline
Sympathetic- neurone release noradrenaline or adrenaline on target tissue
Meds- if panicky give acetyl choline meds to activate para. Or meds to block action or adrenaline (prazosin)
What is REM and non REM sleep?
REM- rapid eye movement, associated with dreaming and skeletal muscles are paralysed. Occurs 80-100 minutes after start of sleep. And then every 90 momutes, lastig 5-30 minutes each cycle. Rapid movement of eyes, and the heart and respiratory rate is irregular. 4-5 cycles a night of rem. If woken up during rem dreams are remembered.
Non REM- 4 stages of sleep, most of our sleep at night, reduction of physiological activity, and brain waves measured by ecg slower, and breathing and heart rate decrease.
What is circadian rhythms??
Bodily changes in 24 hours. The normal fluctuations of the body like hormone secretion, temperatures and other physiological factors.
Can be effected by to a certain extent by external factors like meal times and work patterns.
Changes occur with regular increases and decreases of cellular activities that occur in 24 hours.
What is the pineal gland what does it do?
Serotonin / melatonin
Pineal gland indirectly responds to light.
Suprachiasmatic nucleus is the biological clock and influences pineal gland.
Together they control secretion of hormone melatonin from pineal gland. Darkness stimulates melatonin, light inhibits melatonin.
Melatonin is made from serotonin, both from the amino acid tryptophan, rich in foods like milk, chocolate. Serotonin is associatied with feeling good and relaxation, and melotonin is sleepiness and secreted at night.
Why do we need sleep?
Restoration - rest and repair
Energy conservation - save calories
Brain processing - synaptic processing
What is erythropoiesis?
Formation of new red blood cells from red bone marrow. When dead or lost. As they grow they exclude their nucleus as they fill with haemoglobin. Squeeze in to red reticulocytes to begin circulating around the body.
When less oxygen levels hypoxia. Kidney (receptor) then releases erythropoietin which stimulates red bone marrow (effector) to make erythropoietin (controller) which increases rbc count, increases 02 carrying ability of blood
What is plasma and the functions of plasma proteins??
Steaw coloured sticky fluid made of 91% water and 7% plasma proteins of albumins, a globulins, y globulins and beta globulins
Functions are
Clotting blood
Antibodies are y globulins
Transport substances are carried in blood eg calcium by albumins
Plasma proteins contribute to viscosity of blood helping with resistance in blood vessels increasing bp
What is haemostasis and what are the 3 stages??
Haemostasis is the stemming of blood following damage to the blood vessel.
Vascular spasm
Formation of a temporary platelet plug formation
Co agulation
What is vascular spasm in heamostasis?
Vascular spasm is when the smooth muscle fibres contract in the damages walls of blood vessels. Reducing blood flow to damage. Mimmediate protection
What is platelet plug formation in haemostasis?
Im a damaged blood vessel, collagen fibres are exposed to blood. Platelets stick to the collagen causing a platelet plug which blocks minor bleeding,
Thromboxane makes platelets sticky allowing the plug to form
What is the co agulation phase of haemostasis?
Last but most effective method,
Goal is to convert fibrinogen to fibrin,which then entraps platelets and blood cells and seal the cut. Requires clotting factors that was normally in active.
Substances released from damaged tissues results in prothrombin activator, which activates coagulation.
This causes prothrombin to be converted to thrombin, with calcium present
Thrombin convets soluble fibrinogen to insoluble firbin
Fibrin forms a network of threads which traps platelets and blood cells to form a clot halting bleeding.
Calcium always needs to be present
What is firbinolysis?
Process that breaks down the fibrin clot by firbinolytic agents
What are anti-platelet drugs?? In haemotology
They reduce the risk of clots forming in the blood. Reducing stokes and heart attacks.
Aspirin is an anti platelet drug as it prevents the formation of thromboxane by binding to an exxyme cyclooxegenase (cox) which prevents platelets being able to stick together.
What are anticoagulant? In haemotology like antiplatelet drugs
Anti coagulant drugs reduce ability of blood to clot. Like heparin (what mast cells make) and warfarin which interferes with the action of vitamin K it is a coenzyme of prothrombin
What cofactor is needed in the liver as a clotting factor to produce prothrombin??
Vitamin K
Deficiency leads to bleeding,
What are the cells in muscle tissue and what are their characteristics??
Cardiomyocytes
Lots of mitochondria, need calcium for contraction
Striated mononucleated
Y shaped
Joined by intercalated discs which contain gap junctions which allows ions to move from cell to cell allowing depolarisation,
What are the 3 stages in cardiac cycle?
Atrial systole - contraction of the atrium after SA node depolarises it
Ventricular systole- ventricular contraction after AV node depolarises it
Complete diastole - relaxation of heart where blood is passively filling from atrium in to ventricles (passive ventricular filling)
What dos ECG stand for? And what does it all show?? What is sinus rhythm?
Electrocardiogram
Sinus rhythm is the natural rhythm of the heart,
P wave- depolarisation of atrium
QRS- depolarisation of ventricles
T - repolarisation of ventricles before diastole
What is digoxin?
Glycoside from foxglove plant,used to treat heart problems like atrial fibrillation, effects like able to slow down heart, and help it beat more regularly by distributing concentration of ions in cardiomyocytes and reduces conductivity in av node.
What is blood pressure and what 3factors effect it?
Blood pressure is the force exerted by blood on the inner walls of blood vessels.
Heart rate, blood volume and viscosity, blood vessels in relation to their diameter
What is the equation to calculate blood pressure?
Blood pressure = cardiac output x total peripheral resistance
What is the equation to find out cardiac output?
Co = stoke volume x heart rate
Total volume of blood pumped out of ventricles during a minute
Stroke volume is volume ejected from left ventricle per 1 contraction
What is peripheral resistance?
Peripheral resistance is the resistance to blood flow which is mainly created by the diameter of blood vessels
Controlled by short term nervous system and long term hormones
How can heart rate be controlled?
Baroreceptors (receptor) in aortic arch and internal carotid arteries. Send info to cardiac centre in medulla (in brain stem which is the controller) which is controlled by autonomic PNS parasympathetic and sympathetic nervous systems, heart is the effector by neurones exciting the SA node, AV node and cardiac muscle, increasing heart rate in sympathetic.
How is peripheral resistance regulated?
Baroreceptors in aprtic arch and internal carotid ateries detect lower blood pressure, nerve impulses sent to neurones in the medulla in the vasomotor centre. Which is the controller of the diameter of arterioles. Vasomotor tone in blood vessels is controlled by vasomotor centre, and sympathetic impulses lead to vasoconstriction of smooth muscle. Increases peripheral resistance
What are baroreceptors?
Pressure sensitive receptors which detect changes in the stretch in the artery walls due to blood pressure changes, which sends impulses to vasomotor centre and cardiac centre in medulla
Found in aortic arch and internal carotid arteries
What are antihypertensives? Pharmacology of heart rate
Class of medicines that help to control high blood pressure. Diuretics try and reduce volume of fluid,
Beta - blockers work by blocking effect on adrenaline on the heart, decreasing heart rate and force of contraction
Calcium channel blockers work by blocking the cardiomyocytes from having calcium for contraction. So will dilate blood vessels and reduce the force of contraction
Some try to suppress sympathetic nervous system
What is amygdala hijack and allostatic load?
Amygdala hijack occurs when a threat overwhelms the brain involving emotional distress, anger, impulse and fear taking actions which may later be regretted
Allostatic load- chronic stress with repeated reactions from amygdala leads to wear and tear of the brain and body.
What is the long term stress response? HPA axis (hypothalamic-pituitary-adrenal axis)
Danger detected by amygdala via eyes or ears
Distress signals sent to hypothalamus who is in charge of the stress response stimulates sympathetic system, activating pituitary gland and adrenal gland
Adrenal medulla in adrenal cortex produces adrenaline
CRF is send to Pituitary gland from hypothalamus which makes the pit gland release ACTH
ACTH activates the adrenal cortex to produce cortisol into blood which increases energy availability by increasing glucose and fatty acids in blood. Suppressed immune system and is an anti-inflammatory
What 4 ways can the respiratory system by divided?
Upper respiratory tract- from nose is larynx
Lower respiratory tract- trachea to alveoli
Conduction zones- function of getting air in and out of lungs, warms and filters air. Eg nose pharynx, larynx, trachea, bronchi
Respiratory zone- gas exchange at alveoli, alveolar duct
Functions of respiratory system?
Filter, humidy and warm air Gas exchange Get air in and out of lungs Expel waste products Speech Smell
What are the lungs like?
Two cone shaped organs protected by ribs, sternum and vertebrae.
Divided into regions of lobes, left 2 right 3 lobes
Protected by double layered protective membrane. Called the pleurae. One layer covering the lungs is visceral pleurae, and one covering walls of thorax is the parietal pleurae.
Thin layer between there is pleural fluid
