Cardio-physiology

Question 1

decreasing the radius of an artery by 50%

changes in blood flow

Answer 1

decrease by 1/16

Question 2

supine –> standing position (orthostatic hypotension after sympathectomy)

contractility

Answer 2

increases

to compensate for decrease venous blood return, decrease CO, and arterial pressure

due to decreased response of the baroreceptor mechanism

Question 3

where is systolic blood pressure the highest

Answer 3

renal artery (for some reason)

Question 4

ejection fracture increases,

there will be a decrease in

Answer 4

end-systolic volume…most direct result

Question 5

ventricular extrasystoles

Answer 5

extrasystolic beat would cause decreasd pulse pressure because stroke volume is decreased

the next ‘normal’ beat would produce increased pulse pressure because the contractility of the ventricle will increase (increased Ca2+ left over from extra beat before)

Question 6

2 p-waves before QRS complex

Answer 6

decreased conduction through AVN

Question 7

greates pressure decrease in the circulation at the arterioles because

Answer 7

they have the greatest resistance

Question 8

pulse pressure is determined by

Answer 8

stroke volume

Question 9

when during cardiac cycle is the aortic pressure the highest

Answer 9

reduced ventricular ejection (highest volume)

Question 10

histamine

Answer 10

vasodilation of aterioles

venous contriction

Question 11

CO2 regulates blood flow what organ

Answer 11

brain

Question 12

CO on right side of heart is what % of left side

Answer 12

100%

Question 13

increased size of heart on myocardial O2 consumption

Answer 13

increases it

Question 14

what would increase a kidney’s production of renin

Answer 14

decreased perfusion to that kidney (not always bilateral)