Test 1

Question 1

The stretch on ventricular muscle fibers just before contraction. In the intact heart, this results from stretching of muscle fibers by the blood volume contained w/in the ventricle at the end of diastole. What are 2 good indices of this for the beating heart?

Answer 1

preload; beating heart indices: EDV & EDP

Question 2

the resistance that the ventricle has to overcome to eject blood into vasculature; the force the sarcomere must overcome in order to shorten during systole

Answer 2

afterload

Question 3

intrinsic property of myocardium that accounts for changes in strength of contraction when preload & afterload are unchanged

Answer 3

contractility (inotropy)

Question 4

volume of blood ejected from a ventricle during a single contraction

Answer 4

stroke volume (SV)

Question 5

volume of blood in ventricle at end of ventricular filling; used as measure of ventricular preload

Answer 5

end diastolic volume (EDV)

Question 6

volume of blood left in ventricle at end of ejection

Answer 6

end systolic volume (ESV)

Question 7

fraction of end-diastolic volume that is ejected from ventricle during systole

Answer 7

ejection fraction

Question 8

volume of blood ejected by ventricle per minute

Answer 8

cardiac output

Question 9

ratio of change in volume to change in pressure; ability of hollow organ to distend & increase volume in response to increasing transmural pressure (inside pressure minus outside pressure)

Answer 9

compliance (C)

Question 10

maximum pressure the ventricle can develop for any given ventricular volume at any given inotropic state

Answer 10

end-systolic pressure-volume relationship (ESPVR)

Question 11

relationship between pressure & volume in ventricle at moment ventricle is completely relaxed

Answer 11

end-diastolic pressure-volume relationship (EDPVR)

Question 12

chronotropy

Answer 12

cardiac rate

Question 13

lusitropy

Answer 13

relaxation of the myocardium