***Control of Stroke Volume

Question 1

What is the equation for stroke volume?

Answer 1

SV(h) = EDV - ESV

Question 2

What does EDV stand for?

Answer 2

• end desystolic
• starting volume before contraction

Question 3

What does ESV stand for?

Answer 3

• volume left behind after contraction (end systolic volume)

Question 4

What is the frank-starling mechanism?-

Answer 4

• increased SV with greater ventricular filling

Question 5

More blood in ventricle = ___

Answer 5

• more ejected volume

Question 6

What is frank-starling mechanism influenced by?

Answer 6

• EDV
• Cardiac filling pressure

Question 7

What is contractility? (2)

Answer 7

• stretching of ventricle with increased filling
• change in development of force at a given resting muscle fibre length

Question 8

What is peak isometric tension

Answer 8

• force w/o changing

Question 9

What is the sliding filament theory?

Answer 9

• contraction/muscle shortening
• thin filaments slide over thick

Question 10

What is SNS?

Answer 10

• sympathetic nervous system (fight or flight)

Question 11

What increases contractility during fight or flight?

Answer 11

• epinephrine (adrenaline)
• increased Q