Regulation of arterial blood pressure Flashcards

Question

stimulus= high blood pressure

Answer 1

baroreceptors in carotid sinuses and aortic arch stimulated peak impulses from baroreceptors, stimulate cardioinhibitory centre and inhibit vasomotor centre decreased sympathetic impulses to heart causes decreased heart rate, decreased contractility and decreased CO rate of vasomotor impulses allow vasodilation, decreased resistance decreased CO and R return blood pressure to homeostatic range

Answer 2

baroreceptors in carotid sinuses and aortic arch are inhibited impulses from baroreceptors activate cardioacceleratory centre and stimulate vasomotor centre sympathetic impulses to heart cause increased HR, increased contractility and increased CO vasomotor fibres stimulate vasoconstriction causing increased resistance increased CO and R to return to homeostatic range

Answer 3

parallel vascular beds sympathetic response, non uniform F=P/R consequences of prolonged vasoconstriction is ischaemic damage

Answer 4

vasoconstriction greatest in skeletal muscle less in kidneys least in gut non in heart and brain

Answer 5

massage of carotid sinus distends baroreceptors increases vagal outflow to heart slows SA firing and AV conduction AVN conducts fewer action potentials through to the ventricles less QRS complexes, ventricular rate slows down from dangerously high rates

Answer 6

carotid sinus massage diving reflex valsalva manoeuvre modified valsalva manoeuvre

Answer 7

inhale deeply handheld breath imagine chest and stomach muscles are very tight and bear down as though straining to initiate bowel movement hold this position for short time, 10 seconds breathe out forcibly to release the breath rapidly resume normal breathing

Answer 8

increased intrathoracic pressure increases blood flow from pulmonary circulation into the left atrium, increases left ventricular EDV and SV, compression of the aorta, increasing blood pressure high intrathoracic pressure impedes venous return, decreasing SV and also blood pressure, in this period there is a baroreceptor-mediated increase in heart rate when released, compression on the aorta is stopped and left ventricular filling pressures reduced temporarily as pulmonary vessels re-expand, blood pressure drop VR restored, increases cardiac filling pressures and SV, increases bP, resulting in baroreceptor reflex-mediated bradycardia and subsequent fall in BP to normal levels

Answer 9

SVT S= strain, make 10cc of syringe move V= venous return, passive leg raise T= time, 15 seconds at each stage

Answer 10

decrease in Pa activares RAAS set of responses attempt to increase Pa back to normal most important: effect of aldosterone to increase renal Na+ reabsorption increase Na+ absorption, total body Na+ content increases, increases ECF volume and blood volume increases in blood volume produce an increase in venous return and cardiac output produces increase in Pa direct effect of angiotensin 2 to constrict arterioles, increasing TPR and contributing to increase in Pa

Answer 11

convert angiotensinogen to angiotensin 1

Answer 12

converted to angiotensin 2 by ACE in lungs and kidneys

Answer 13

using AT1 R causes increased vasoconstriction, increases TPR increase thirst increases Na+, H+ exchange, increases Na+ reabsorption, increases ECF volume increased aldosterone, increased Na+ reabsorption, increased ECF volume all increase Pa towards normal

Answer 14

using ACE 2 Ang 1-7

Answer 15

using MasR leads to vasodilation

Answer 16

peripheral chemoreceptors central chemoreceptors antidiuretic hormone cardiopulmonary (low pressure) baroreceptors

Answer 17

for O2 in carotid bodies, near bifurcation of common carotid and aortic bodies have high blood flow, chemoreceptors primarily sensitive to decrease in partial pressure of O2 chemoreceptors sensitive to increases in partial pressure CO2 and decreases in pH, particularly when simultaneously decreased reponse of peripheral to decreased arterial P O2 greater than when P CO2 is increased or pH decreased

Answer 18

Cushing reaction shows how cerebral chemoreceptors maintain cerebral flow intracranial pressure increases there is compression of cerebral arteries, decreased perfusion of the brain immediate PCO2 increase and pH decrease as CO2 generated from brain tissue not adequately removed by blood flow medullary chemoreceptors respond to these changes by directing increase in sympathetic outflow to blood vessels increase TPR and increase Pa

Answer 19

Cushing reaction shows how cerebral chemoreceptors maintain cerebral flow intracranial pressure increases there is compression of cerebral arteries, decreased perfusion of the brain immediate PCO2 increase and pH decrease as CO2 generated from brain tissue not adequately removed by blood flow medullary chemoreceptors respond to these changes by directing increase in sympathetic outflow to blood vessels increase TPR and increase Pa

Answer 20

secreted by posterior lobe of pituitary gland regulates body fluid osmolarity and regulation of arterial blood pressure has 2 receptors V1 and V2

Answer 21

in vascular smooth muscle cause vasoconstriction of arterioles and increased TPR

Answer 22

principal cells of renal collecting ducts involved in water reabsorption in collecting ducts and maintenance of body fluid osmolarity

Answer 23

increases in serum osmolarity decreases in blood volume and blood pressure

Answer 24

located in veins, atria and pulmonary arteries sense changes in blood volume/fullness of vascular system located on venous side of circulation, where most of blood volume is held increase in blood volume, resulting increase in venous and atrial pressure detected by cardiopulmonary baroreceptors return blood volume to normal by increasing excretion of Na+ and water

Answer 25

decreases Pa produces decreased stretch on the baroreceptors and decreased firing rate of the carotid sinus nerve information is received in the nucleus tracts solitaires of the medulla produces coordinated decrease in parasympathetic activity and increase in sympathetic activity heart rate, contractility increase causing increased CO increased arteriole constriction producing increase in TPR increased constriction of the vieins so decreased unstressed volume and increased venous return

Answer 26

increase in angiotensin 2 increased TPR increased aldosterone increased Na+ reabsorption increased blood volume

Answer 27

decreased Pc increased fluid absorption increased blood volume

Answer 28

when cold water stimulates the sensory receptors of the trigeminal nerve and receptors in the nasopharynx and oropharynx results in 3 changes 1. Apnoea, whilst apnoea changing concentrations of o2 and CO2 in blood stimulate chemoreceptors, increasing vagal drive and decreasing heart rate 2. bradycardia, intense vagal inhibition decreases the slope of the pacemaker action potential and decreased oxygen consumption 3. peripheral vasoconstriction in splanchnic, renal and skeletal muscle vascular bed the strong sympathetically mediated vasoconstriction increases TPR allowing blood pressure to be maintained despite profound bradycardia

Answer 29

decrease in renal perfusion pressure causes release of renin from JG cells into plasma

Answer 30

conversion of plasma angiotensinogen to angiotensin 1

Answer 31

in the lungs and the kidneys by ACE into angiotensin 2

Answer 32

agonist at AT 1 receptors a GPCR

Answer 33

arterioles, causes vasoconstriction adrenal cortex, induces release of aldosterone proximal convoluted tubules, stimulates increased Na+/H+ exchange increasing reabsorption of Na+

Answer 34

increases expression of ENaCs on apical membrane and sodium pump on basolateral membrane

Answer 35

hypothalamus to increase thirst and water intake pituitary gland to release ADH which reduces water loss by up regulating aquaporins in th CD of the kidney

Answer 36

increased TPR increased sodium reabsorption to increased ECF volume to increased BP increased water retention to increased body fluid

Regulation of arterial blood pressure Flashcards

(60 cards)