Cardiac Output

Front 1

Stroke Volume is what?

Back 1

amount of blood pumped out with every heart beat

Front 2

Cardiac output is adjusted by changes in what?

C.O. = ?

Back 2

stroke volume, heart rate
CO = SV x HR
(ml/min) = (ml/beat) x (beat/min)

Front 3

Stroke volume is regulated by what 3 things?

Back 3

1. EDV (preload)
2. total peripheral resistance
3. contractility

Front 4

How are EDV (preload), total peripheral resistance, and contractility proportional to stroke volume?

Back 4

EDV/preload and contractility are DIRECTLY proportional
Total Peripheral Resistance is INVERSELY proportional

Front 5

Atrial Reflex adjusts what in response to venous return?

Back 5

heart rate

Front 6

Stretch receptors in right atrium trigger what through increased sympathetic activity?

Back 6

increase in heart rate

Front 7

What are 2 Factors that affect EDV (end-diastolic volume)?

Back 7

Filling time and Venous Return

Front 8

What is Stroke Volume? (formula)

Back 8

SV = EDV - ESV

Front 9

What is Venous Return?

Back 9

rate of blood flow during ventricular diastole

Front 10

What is Preload?

Back 10

the degree of ventricular stretching during ventricular diastole

Front 11

Preload is directly proportional to what?

Back 11

EDV

Front 12

When are EDV and stroke volume low, and myocardium stretches less?

Back 12

at rest

Front 13

With exercise, EDV, myocardium, and stroke volume do what?

Back 13

EDV increases,
myocardium stretches more,
and stroke volume increases

Front 14

The Frank–Starling Principle states what?

Back 14

As EDV increases, stroke volume increases

Front 15

Ventricular expansion is limited by:

Back 15

myocardial connective tissue,
the fibrous skeleton,
and the pericardial sac

Front 16

What is End-Systolic Volume (ESV)?

Back 16

amount of blood remaining in the ventricle at the end of ventricular systole (heart contraction)

Front 17

There are 3 Factors that Affect ESV, what are they?

Back 17

Preload, Contractility, and Afterload

Front 18

what changes occur in the heart during excercise?

Back 18

cardiac output increases:
because heart rate increases and the ventricles contract more forcefully which increases stroke volume; increased SV increases Blood pressure and peripheral resistance increases.

Front 19

What is Contractility?

Back 19

force produced during contraction

Front 20

what is mean arterial pressure (MAP)?

Back 20

Blood pressure
(average blood pressure in aorta)

Front 21

What is Afterload?

Back 21

the tension the ventricle produces to open the semilunar valve and eject blood

Front 22

what is the formula to determin MAP?

Back 22

MAP = CO x PR

Front 23

what is cardiac output (CO)?

Back 23

the amount of blood pumped by the heart per minute

Front 24

what is the formula for determining CO?

Back 24

CO = SV x HR

Front 25

what is cardiac reserve?

Back 25

difference between CO at rest and maximum CO

Front 26

what is Peripheral Resistance (PR)?

Back 26

PR is total resistance against which blood must be pumped

Front 27

As afterload increases, what decreases?

Back 27

stroke volume

Front 28

what is the formula to determine blood pressure?

Back 28

BP = CO x PR

Front 29

The difference between resting and maximal cardiac output is called?

Back 29

Cardiac Reserve

Front 30

what does increased volume in the heart do?

Back 30

increases the force of the contraction (Starling's Law)

Front 31

Stroke Volume is equal to what percent of end-diastolic volume?

Back 31

60%

Front 32

Force of contraction of the cardiac myocytes also relates to:

Back 32

length of the muscle fiber short = low force of contraction
medium = high force of contraction
long - lower force of contraction

Front 33

What is the relationship of stroke volume with EDV and ESV?

Back 33

SV = EDV — ESV

Front 34

Contraction strength can be intrinsically controlled by:

Back 34

Frank-Starling Law
EDV increase causes contraction strength and stroke volume to increase

Front 35

What is Ejection fraction?

Back 35

the percentage of EDV represented by SV

Front 36

Describe extrinsic control of contractility.

Back 36

1. Positive inotropic effect: sympathetic/adrenal norep./ep. increase contractility
2. Negative inotropic effect: Beta-blockers decrease contractility

Front 37

Factors that affect venous return:

Back 37

1. Venous Pressure: pressure increases venous return by:
- venule pressure > vena cava pressure
- veins become stiff from sympathetic stimulation, decrease volume, pressure increase
- skeletal muscle pumps ---> pressure increase
- pressure diff between abdominal + thoracic cavities helps venous return

2. Blood Volume

Front 38

Oncotic Pressure

Back 38

Oncotic Pressure = difference between the osmotic pressures of blood plasma and interstitial fluid

Front 39

what are the intrinsic factors that increase mean arterial pressure?

Back 39

increased blood volume, excercise, changing from a standing to a lying down position - increased venous return, increased end-diastolic volume (which increases force of contraction) which increases CO, which increases MAP

Front 40

What are the 3 ways that the kidneys regulate LOW blood volume

Back 40

1. Anti-Diuretic Hormone from post. pituitary
2. Aldosterone from adrenal cortex (causes H20 reabsorb)
3. Renin enzyme ----> Angiotensin II
- Angiotensin II stimulates: vasoconstriction, thirst, aldosterone prod.

Front 41

How does Autonomic Activity affect contractility through sympathetic stimulation?

Back 41

– NE released by postganglionic fibers of cardiac nerves
– epinephrine and NE released by adrenal medullae
– causes ventricles to contract with more force
– increases ejection fraction and decreases ESV

Front 42

How does Autonomic Activity affect contractility through parasympathetic stimulation?

Back 42

– acetylcholine released by vagus nerves
– reduces force of cardiac contractions

Front 43

What are 3 Heart Rate Control Factors?

Back 43

1. Autonomic nervous system:
sympathetic and parasympathetic
2. Circulating hormones
3. Venous return and stretch receptors

Front 44

What are the ways that the kidneys regulate HIGH blood volume

Back 44

Atrial natriuretic peptide: released by atria in response to stretch
- inhibits ADH secretion

Front 45

What does sympathetic stimulation do to the heart?

Back 45

Supplied by cardiac nerves, increases heart rate and force of contraction, epinephrine and norepinephrine released

Front 46

During rest, under what stimulation is the heart?

Back 46

The SA node is slowed down by parasympathetic regulation via the vagus nerve and acetylcholine.

Front 47

During exercise, under what stimulation is the heart?

Back 47

sympathetic stimulation, Supplied by cardiac nerves, increases heart rate and force of contraction, epinephrine and norepinephrine released

Front 48

what does increased sympathetic stimulation do to end systolic volume?

Back 48

decreases end systolic volume because more blood is ejected from stronger contractions

Front 49

at rest, the ___________ nervous system releases _______ to _________ the heart rate at the SA node.

Back 49

parasympathetic
acetylcholine
decrease

Front 50

the parasympathetic N.S. ______ heart activity via _________ secreted from the ___________

Back 50

decreases
acetylcholine
vagust nerve

Front 51

the sympathetic N.S. ______ heart activity via _________ secreted from the _______

Back 51

increases
norephinephrine
adrenal medulla

Front 52

what happens if there is a sudden increase in pH (a sudden decrease in CO2)

Back 52

we want to send less blood to lungs to keep CO2 in the blood longer, so:
increased parasympathetic stim which decreases heart rate, which sends less blood to the lungs, so CO2 increases (pH decreases)

Front 53

at rest, what happens if there is a sudden decrease in pH (a sudden increase in CO2)?

Back 53

increased sympathetic stim increases heart rate and SV to increase blood flow to lungs where more CO2 can be blown off and pH will increase as CO2 levels decrease

Front 54

at the cardioregulatory center, whenever parasympathetic stim is increased, sympathetic stim is ___________

Back 54

decreased

Front 55

at the cardioregulatory center, whenever sympathetic stim is increased, parasympathetic stim is ___________

Back 55

decreased

Front 56

Extrinsic blood-flow control
(entire body - heart/kidney)

Back 56

- Sympathetic norepinephrine (constrict)
- Para/sympathetic acetylcholine (dilate)
- bradykinin, nitric oxide, prostaglandin I2 (vasodilate)

Front 57

Intrinsic blood-flow control? (heart/kidney only)

Back 57

1. Myogenic: smooth muscle in vessels can constrict or dilate on their own (stretch receptors)

2. Metabolic: Vasodilation of vessels due to change in pH, CO2, O2, K+ (chemoreceptors)

Front 58

Coronary blood-flow control?

Back 58

Sympathetic norepinephrine: constrict
Adrenergic epinephrine: dilate

Front 59

Heavy exercise blood flow rate (ml/min)?

Back 59

20,000 ml/min

Front 60

Skeletal muscle blood-flow control?

Back 60

Sympathetic acetylcholine: dilate
Adrenergic epinephrine: dilate