intrinsic and extrinsic control of stroke volume

Question 1

Stroke volume usually referring to right or left ventricle?

Answer 1

left ventricle because its the one that pushes blood into aortic arch

Question 2

isovolumetric contraction: heart contracts but two valves are closed, no volume change as a result. contraction causes pressure spike or decrease?

Answer 2

spike

Question 3

Isovolumetric relaxation: no change in volume, relaxation causes pressure to spike or drop?

Answer 3

drop

Question 4

stroke volume = endiastolic volume - end systolic volume. refers to ??? volume

Answer 4

ventricular volume

Question 5

stroke volume depends on preload: amount of muscle stretch immediately prior to ???

Answer 5

contraction

Question 6

Frank-Starlin Law (preload and SV) stretching myocytes before activation leads to a more powerful force generation and therefore greater ???

Answer 6

stroke volume

Question 7

TRUE or FALSE: length-tension and FS law: 75% of sarcomere length shortened/overlapped, tension is greatly reduced

Answer 7

True

Question 8

TRUE or FALSE: Length-tension and FS law: 100% of sarcomere length at resting length = optimal sarcomere operating length = greater ability for sliding filament mechanism to occur

Answer 8

TRUE

Question 9

TRUE or FALSE: Stroke Volume depends on afterload (MAP/downstream blood pressure= BP in aorta that the contraction is fighting against to open up semi-lunar valve)

Answer 9

TRUE

Question 10

downstream BP that impedes cardiac emptying: delays aortic valve opening because valve cannot open until ventricular pressure is less or more than aortic pressure?

Answer 10

more

Question 11

does the aortic pressure easily become higher than ventricular pressure? if so, would valves close rapidly or slowly in response?

Answer 11

YES, valves rapidly close

Question 12

Stroke volume and contractility: increase in contractility = increase time heart contracts (i.e it contracts for longer) = more blood ejected out. Caused by increased ??? levels in blood

Answer 12

Ca2+ levels in blood

Question 13

Stroke volume also depends on Heart rate: increased heart rate = increased stroke volume (up to a certain point) and cardiac output due to ??? entry into blood

Answer 13

increased Ca2+ entry

Question 14

(Extrinsic) SNS innervation of contractile cells: noradrenaline activation = increased or decreased contractility? this causes increased SV

Answer 14

increased contractility

Question 15

(Extrinsic) PNSS innervation of contractile cells: acetylcholine. occurs mainly in ??? node = HR bradycardia. Contractile cells = minimal PNS innervation of cardiac muscle = minor decrease in contractility

Answer 15

SA node