Cardio-physio-cardiac output-slivkoff

Question 1

What 3 determinants of stroke volume?

Answer 1

afterload, preload, and contractility

Question 2

Stroke volume X HR =

Answer 2

cardiac output

Question 3

Afterload has a positive/negative affect on stroke volume?

Answer 3

negative

Question 4

Preload and contractility have what kind of effect on stroke volume?

Answer 4

positive, as either increase, stroke volume increases

Question 5

What is preload?

Answer 5

filling pressure

Question 6

What is afterload?

Answer 6

arterial pressure opposing ejection

Question 7

As more venous return enters the heart, the cardiac output increases. This process describes increased preload or afterload?

Answer 7

Preload

Question 8

The more blood you give the heart, the more/less it is going to pump out

Answer 8

more

Question 9

There is an ideal length that maximizes the overlap between actin and myosin and maximizes generated.

Answer 9

tension

Question 10

What are some ways to change the number of crossbridges being made in the sarcomere?

Answer 10

1. alter preload (either more or less)
2. more Ca2+

Question 11

According to the Frank-Starling Mechanism diagram, as stroke volume increases, ventricular end diastolic volume .

Answer 11

inceases, but it can platuea and decrease if there is too much of either

Question 12

What 4 main factors can change preload?

Answer 12

1. increase in blood volume (increase preload)
2. venoconstriction (increase preload)
3. skeletal muscle pump (increase preload)
4. nitroprusside (venodilation) -decrease preload

Question 13

How does inspiration and expiration change preload?

Answer 13

inspiration increases preload

expiration decreases preload

Question 14

What are the main funcitons of ACE inhibitors and angiotensin II receptor blockers?

Answer 14

the decrease overall blood volume which in turn decreases BP

Question 15

What kind of effect does tricuspid and mitral valve stenosis have on stroke volume?

Answer 15

decreases stroke volume by decreasing preload and ventricular outflow

Question 16

What kind of effect does aortic stenosis have on preload or stroke volume?

Answer 16

Aortic stenosis would increase diastolic ventricular pressure and lead to decreased ventricular filling, leading to decreased preload and stroke volume

Question 17

What kind of effect does atrial tachycardia have on stroke volume?

Answer 17

It would lead to a fib and decreased ventricular filling time, which would not leave enough time to fill up ventricle

Question 18

Changing from an upright to supine position does what to preload?

Answer 18

It increases preload as there is less blood pooling in lower parts of body

Question 19

What term describes the arterial pressure right after the aortic valve (pressure through all the major arteries)?

Answer 19

afterload

Question 20

High BP is an increase/decrease in afterload (arterial pressure opposing ejection)?

Answer 20

increase

Question 21

Increasing total peripheral resistance (TPR) would have what effect on afterload?

Answer 21

Increase afterload and BP

Question 22

How does decrease of systemic vascular resistance affect afterload and stroke volume?

Answer 22

It woud decrease afterload and therefore increase SV

Question 23

What effect does hydralazine, ACE inhibitiors, angiotensin II receptor blockers, have on SV and afterload?

Answer 23

They are all vasodilators, would decrease BP, which would decrease afterload and increase SV

Question 24

Exercise causes an increase/decrease in vascular resistance?

Answer 24

decrease in vascular resistence, which would increase stroke volume and decrease afterload

Question 25

Decreased pulmonary resistance caused by phosphodiesterase inhibitors (vasodilator) would have what effect on the right ventricle?

Answer 25

Decrease afterload and increase SV to right ventricle

Question 26

What does increased systemic and or peripheral vascular resistance (chronic HTN and vasopressors) and aortic valve stenosis do to afterload and SV?

Answer 26

Increase afterload and decrease SV

Question 27

What is another way to describe wall stress?

Answer 27

afterload

Question 28

Wall stress **increases/decreases** with increased ventricular pressure (HTN) and increase ventricular radius (dilated cardiomyopathy)?

Answer 28

increases

Question 29

Wall stress i**ncreases/decreases** with increased ventricular thickness (hypertrophy)?

Answer 29

decreases (more myocytes taking on stress, reduces the stress felt by each myocyte)

Question 30

dP/dt (pressure/time) could be a measure of what?

Answer 30

contractility (steeper line means more contractility)

Question 31

How to calculation ejection fraction?

Answer 31

Stroke volume/ end diastolive volume

Question 32

What do catecholamines and positive inotropes (digoxin) do to heart contractility?

Answer 32

increases contractility

Question 33

What does loss of myocardium, B-blockers, non-dihydropyridin Ca2+ channel blockers, and dilated cardiomyopathy do to contractility?

Answer 33

Decreases contractility

Question 34

What effect does decreased extracellular Na+ (due to decreased Na+/Ca2+ exchanger activity) have on contractility?

Answer 34

Increases contractility as there is more Ca2+ left in the heart

Question 35

What effect does digitalis have on contractility?

Answer 35

It inhibits the Na+/K+ pump, which decreases the intracellular Na+, which decreases activity of the Na+/Ca2+ exchanger, leading to increase Ca2+ in the heart and increased contractility

Question 36

What is the effect of thyroid hormones on contractility?

Answer 36

Increases contractility (by making more B1 adrenergic receptors)

Question 37

What effec do B1-receptor blockers have on contractility?

Answer 37

decreases contractility

Question 38

What effect does hypoxia have on contractility?

Answer 38

Decreases it

Question 39

What do narcotic overdose, hypercapnia (increased CO2), hyperkalemia, and acidosis have in common as concerning contractility?

Answer 39

they decrease contractility

Question 40

What effect does increase venous tone have on preload?

Answer 40

contraciton of venous vessels enhances venous return and preload

Question 41

As blood moves through the heart, increased arterial constriction would lead to **increased/decreased** peripheral resistance, which would **increase/decrease** stoke volume?

Answer 41

increased peripheral resistance; decreased stroke volume

Question 42

Arterial **vasodilation/ vasoconstriction** leads to increased SV and CO?

Answer 42

vasodilation (less pressure for the heart to fight against)

Question 43

Venous **vasodilation/venoconstriction** leads to decreased SV and CO?

Answer 43

vasodilation (as there is less oompf of the blood entering the heart)

Question 44

More blood volume (venous return) and increased venous tone (activated by SNS) does what to preload?

Answer 44

Increases preload

Question 45

What does an increase ventricular radius and ventriclar pressure do to afterload according to LaPlace's law (wall stress = increased afterload)?

Answer 45

increases afterload, decreasing SV and CO

Question 46

According to LaPlace's law, how does increased ventricular thickness affect wall stress, and therefore afterload?

Answer 46

Ventricular thickness decreases wall stress (shared load by more myocytes) and decreases afterload

Question 47

What is the product of CO and systemic vascular resistance?

Answer 47

Blood pressure

Question 48

What do SNS a1 receptors, angiotensin II, endothelin, and O2 have in common?

Answer 48

They decrease arteriolar diameter, vasoconstriction

Question 49

What do B2 receptors, NO, adenosisn, decreased pH, and prostaglandins have in common?

Answer 49

They increase arteriolar diameter, leading to vasodilation

Question 50

What is the pressure that is measured when the heart has stopped?

Answer 50

Mean circulatory filling pressure or mean systemic pressure

Question 51

Cardiac output will always match _._

Answer 51

venous return

Question 52

Given the same contractility, if you increase volume into the system (IV), what happens to the mean circulatory filling pressure (when heart is stopped)?

Answer 52

The mean circulatory filling pressure will increase, which will result in an increase in CO or venous return?

Question 53

which way does the vascular funtion curve shift with increased blood volume?

Answer 53

It shifts the curve up

Question 54

which way does the vascular funtion curve shift with decreased blood volume?

Answer 54

It shifts the curve down

Question 55

If we increase contractility, what type of effect will occur with the cardiac function curve?

Answer 55

The curves shifts upward

Question 56

If we decrease contractility, what type of effect will occur with the cardiac function curve?

Answer 56

The curve shifts down.

Question 57

What happens to the curves during increased total peripheral resistance (TPR or vasoconstriction)?

Answer 57

The cardiac funtion curve and vascular function curve shift down but the pivot point stays the same.

Question 58

What happens to the curves during decreased total peripheral resistance (TPR or vasodilation)?

Answer 58

They both increase but the pivot point stays the same.

Question 59

Review diagram

Answer 59

Question 60

What happens to the pressure volume loop with excercise?

Answer 60

SV increases, EDV increases, contractility increases, decrease in afterload. ( We have not added more blood but squeezed out the blood in the veins with the skeletal muscle pumps).

Question 61

Review diagram

Answer 61