cardiac physiology

Question 1

primary function of the cardiovascular system

Answer 1

Pump blood
Deliver oxygen and nutrients
Remove CO2 and byproducts of cellular metabolism

Question 2

secondary function of cardiovascular systems

Answer 2

Maintain heat temperature
Deliver white blood cells for defense and hormones

Question 3

Cardiac output

Answer 3

5- 6 L per minute

volume of blood ejected out of left ventricle into systemic vasculature per minute

CO= HR x SV

Question 4

cardiac index

Answer 4

CO/body surface area

Question 5

stroke volume

Answer 5

amount of blood pumped from ventricles with each contraction/ beat

55-100ml

Question 6

rate pressure product RPP

Answer 6

an index of myocardial O2 consumption; reflecting cardiac fitness

RPP= HR X systolic bp/1000

Question 7

Regulation of stroke volume

Answer 7

myocardial cell length

Myocardial cell contractility influenced by intrinsic myocardial stretch

Frank Starling mechanism

Question 8

preload

Answer 8

blood Returning to heart or end diastolic volume

effect of stretch prior to contraction

Extrinsic activity of sympathoadrenal system

Question 9

afterload

Answer 9

blood ejected out of heart is influenced by the pressure generated in ventricle compared to pressure in systemic vasculature

Question 10

intrinsic heart rate regulation

Answer 10

SA and AV nodes

Sympathetic- increase heart rate via SA

parasympathetic- slows heart rate via SA

Question 11

extrinsic heart rate regulation

Answer 11

Neural influences

Peripheral
Cortical

Question 12

sympathetic nerve endings

Answer 12

Beta adrenergic receptors in myocardial wall

1- vasodilates coronary arteries
2- increase heart rate rate via catecholamines
3- cardio accelerator center in medulla

Question 13

Parasympathetic influence

Answer 13

1- vasoconstricts coronary arteries
2-decrease the heart rate through the action of acetylcholine via vagus nerve
3-cardio inhibitory in medulla

Question 14

HR chronotrophic effects

Answer 14

+ chronotrophic effects if HR is high

• chronotrophic effects if HR is low

Question 15

contractility- ionotrophic effects

Answer 15

+ iontrophic effects if contractility is high

• iontrophic effects if contractility is low

Question 16

What has a positive influence on stroke volume?

Answer 16

Preload
Sympathetic outflow to heart
Circulating epinephrine
Circulating norepinephrine

Question 17

What has a negative influence on stroke volume

Answer 17

Afterload
Parasympathetic outflow to the heart

Question 18

What has a positive influence on heart rate?

Answer 18

preload
Sympathetic outflow
Circulating epinephrine and norepinephrine

Question 19

what has a negative influence on heart rate

Answer 19

Parasympathetic outflow

Question 20

Coronary blood flow

Answer 20

squeezed during systole, but perfuse myocardium during diastole

regulated by autonomic nervous system

Diastolic pressure is primary determinant of coronary pressure

Question 21

Ejection fraction

Answer 21

good indicator of cardiac function

Ratio of volume of blood ejected out of ventricles relative to volume of blood by ventricles

60-70% is normal

Question 22

venous return

Answer 22

effected by two factors

Total blood volume
Pressure within venous vasculature

Question 23

blood flow patterns change at the result of

Answer 23

sympathetic nervous system action

Question 24

blood flow to muscles during exercise release of norepinephrine

Answer 24

vasoconstrict blood to digestive organs, kidneys, thus redirecting to skeletal muscle

Question 25

determinants of myocardium metabolic rate is

Answer 25

rate pressure product= HR X systolic BP / 1000

Question 26

aging and cardiovascular system

Answer 26

L Ventricle wall thickness increases increase vascular thickness Maximum oxygen uptake and cardiac output reduce

Question 27

cardiac muscle

Answer 27

Striated Involuntary Branched Single nucleated Intercalated discs troponin and tropomyosin Calcium from ECF and ER Self exciting tissues EC coupling

Question 28

Venous capacity

Answer 28

Capacity of the veins

Question 29

increase in CVP

Answer 29

The pressure in the thoracic veins SVC and IVC

Question 30

EDV

Answer 30

Max blood in ventricles before a contraction

Question 31

ESV

Answer 31

Maximum amount of blood in ventricle after contraction

Question 32

MAP

Answer 32

mean arterial pressure Pressure in the aorta during one cardiac cycle Influences blood delivered to the organs

Question 33

Hematocrit normal value

Answer 33

45%

Question 34

Red blood cell count normal value

Answer 34

5×10 ^12 cells/L

Question 35

Hemoglobin normal value

Answer 35

15 g/dL

Question 36

White blood cell count, normal value

Answer 36

5×10 ^9 cells/L

Question 37

platelets, normal value

Answer 37

250×10 ^9 cells/L

Question 38

plasma proteins, normal value

Answer 38

7 g/dL

Question 39

Na normal value

Answer 39

140 mEq/L

Question 40

Cl normal value

Answer 40

100 mEq/L

Question 41

K normal value

Answer 41

3.5-5 mEq/L

Question 42

Parasympathetic preganglion fibers release

Answer 42

Acetylcholine

Question 43

sympathetic preganglion fibers release

Answer 43

Acetylcholine

Question 44

parasympathetic post ganglionic receptors

Answer 44

Nicotinic cholinergic

Question 45

Sympathetic post ganglionic receptors

Answer 45

nicotinic cholinergic

Question 46

Parasympathetic post ganglionic fibers release

Answer 46

acetylcholine

Question 47

Sympathetic postganglionic fibers release

Answer 47

Epinephrine

Question 48

Acetylcholine binds to

Answer 48

Muscarinic cholinergic receptors on the effector organ

Question 49

epinephrine binds to

Answer 49

adrenergic receptors on the effector cardiac muscle