Notes in Physiology of the Cardiovascular System LECTURE 20

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Published	01/07/2025	what are the two portal systems?{{c1::hepatic portal system}}{{c1::hypothalamus and anterior pituitary}}
Published	01/07/2025	when the heart contracts - {{c1::systole}} - {{c1::the organs get blood}}when the heart relaxes - {{c1::diastole}} - {{c1::the heart ge…
Published	01/07/2025	stroke volume (SV): {{c1::volume of blood pumped by left ventricle per beat (into aorta)}}
Published	01/07/2025	cardiac output (Q): {{c1::volume of blood pumped by heart per unit time (L/min)}}
Published	01/07/2025	perfusion: {{c1::passage of blood through circulatory system to body's tissues (ml/min/g of tissue)}}
Published	01/07/2025	organ blood perfusion:perfusion of {{c1::brain and kidney}} relatively fixedperfusion of {{c1::skin, muscles, gut}} very variable
Published	01/07/2025	preload (EDV): {{c1::degree to which ventricles are filled at the end of diastole just prior to systolic contraction (measured as end-diaatolic v…
Published	01/07/2025	contractility: {{c1::innate ability of the myocardium to contract}}
Published	01/07/2025	afterload: {{c1::resistance against which the left ventricle must eject the stroke volume from heart (measured as aortic pressure during systole …
Published	01/07/2025	compliance (C): ability of a blood vessel to expand and contract with changes in {{c1::pressure}} (measured as unit of volume change per unit of …
Published	01/07/2025	factors affecting the heart rate?{{c1::atrial reflex}}:manipulated by {{c1::autonomic innervation/hormones = changes heart rate}}
Published	01/07/2025	what are the three components of stroke volume?{{c1::preload}}{{c1::contractility}}{{c1::afterload}}
Published	01/07/2025	what is preload affected by?{{c1::venous return}}{{c1::filling time (time it takes for heart to fill)}}
Published	01/07/2025	what is contractility affected by?{{c1::autonomic innervation}}{{c1::hormones}}
Published	01/07/2025	how can preload affect both EDV and ESV?increased preload = {{c1::high}} EDVincreased preload = {{c1::decreased}} ESV
Published	01/07/2025	what is afterload affected by?{{c1::vasoconstriction/vasodilation}}
Published	01/07/2025	what lowers preload?low {{c1::blood volume/venous blood pressure}}{{c1::impaired atrial contraction (e.g. AF)}}increased {{c1::heart rate imparing ven…
Published	01/07/2025	what lowers contractility?{{c1::parasympathetic}} stimulation{{c1::acetylcholine}}{{c1::hypoxia}}high {{c1::potassium levels}}low {{c1::calcium l…
Published	01/07/2025	what lowers afterload?{{c1::decreased SVR (Systemic Vascular Resistance)}}
Published	01/07/2025	what increases preload?{{c1::fast filling time}}{{c1::increased venous return}}
Published	01/07/2025	what increases contractility?{{c1::sympathetic}} stimulation{{c1::adrenaline and noradrenaline}}high intracellular {{c1::calcium ions}}high blood…
Published	01/07/2025	what increases afterload?{{c1::increased SVR (vascular resistance)}}
Published	01/07/2025	*!what is the Frank-Starling mechanism?{{c1::stroke volume increases in response to increase in volume of blood in the ventricles before contraction w…
Published	01/07/2025	what are the extrinsic controls of circulation?{{c1::autonomic vasomotor nerves}}{{c1::Renin - Angiotensin - Aldosterone}}{{c1::adrenaline}}{{c1::ADH/…
Published	01/07/2025	how do the autonomic vasomotor nerves control circulation?sympathetic - {{c1::vasoconstriction and vasodilation}}parasympathetic - {{c1::vasodilation}…
Published	01/07/2025	the parasympathetic nervous system consists of:{{c1::brainstem}}{{c1::cranial nerves and sacral outflow}}{{c1::end organ ganglia}}{{c1::postganglionic…
Published	01/07/2025	what does the sympathetic nervous system consist of?{{c1::brainstem}}{{c1::spinal cord}}{{c1::preganglionic fibres (ACh)}}{{c1::spinal ganglia}}{{c1::…
Published	01/07/2025	no extrinsic control; heart beat = {{c1::approx. 100 bpm}}during rest/sleep; parasympathetic nervous system predominates so heart beat = {{c…
Published	01/07/2025	effect of noradrenaline in the heart:receptors: a1, b1 and b2inotropy - increase in {{c1::tone in circulation}}chronotropy - increased {{c1::speed of …
Published	01/07/2025	noradrenaline in:a1 and a2 cause {{c1::vasoconstriction}}B2 causes {{c1::vasodilation}}
Published	01/07/2025	acetylcholine binds to {{c1::M2}} receptors on the heart and {{c1::inhibits}} contraction of cardiac myocytes
Published	01/07/2025	what are the three mechanisms which stimulate the release of renin?{{c1::baroreceptors in carotid sinus}} detect decrease in blood pressure, act …
Published	01/07/2025	renin is mainly released from: which cells in which arteriole of the renal glomerulus?{{c1::juxtaglomerular cells in afferent arteriole of renal glome…
Published	01/07/2025	what does renin cause?{{c1::angiotensinogen}} to be cleaved to form {{c1::angiotensin I}}
Published	01/07/2025	where and how does ACE act?what is the most active peptide in RAAS?{{c1::vascular endothelium,}} especially in {{c1::lungs}} contains ACE{{c…
Published	01/07/2025	what are the two Ang-II receptors? - what do they do?{{c1::Type 1 receptors: cause vasoconstriction, cell proliferation, inflammatory responses, blood…
Published	01/07/2025	what are the effects of angiotensin II on the CVS?- what 3 things are released- what 2 things are increased?- what 2 other things are stimulated? {{c1…
Published	01/07/2025	angiotensin II and aldosterone:where does ang-II act? what does it stimulate the release of?what does it effect in the nephron?what is reabsorbed?this…
Published	01/07/2025	nor/adrenaline effect on kidneywhat is adrenaline released by?{{c1::released by adrenal medulla (only has preganglionic fibres)}}Receptor stimulation …
Published	01/07/2025	ADH is released during {{c1::hypovolaemic}} shocksynthesised in the {{c1::hypothalamus}} and released from {{c1::posterior pituitary gland}}relea…
Published	01/07/2025	what are the 2 natriuretic peptides released by the heart?{{c1::atrial natriuretic peptide (ANP)}}{{c1::brain natriuretic peptide (BNP)}}
Published	01/07/2025	what are natriuretic peptides?produced, stored and released by {{c1::atrial myocytes}} mainly in response to {{c1::atrial distention}}what is the…
Published	01/07/2025	cardiac output = {{c1::stroke volume x heart rate}}
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