Cardiac Physiology Flashcards Preview

Fundies First Module--First Exam > Cardiac Physiology > Flashcards

Flashcards in Cardiac Physiology Deck (124):
1

vessels with elastic, smooth muscle, and connective tissue

arteries

2

smallest branches of arteries

arterioles

3

site of highest resistance to flow

arterioles

4

arterial system innervated by the _______ NS

Sympathetic

5

single cell endothelium walled blood vessels

capilaries

6

site of exchange of nutrients, waste products, (H2O, glucose, CO2)

capillary beds

7

vasoactive substance examples

epinephrine( will close capillary beds), acids (normal pH 7.4ish), histamine

8

for hives or allergic reaction

antihistamines

9

histamine released by

mast cells

10

_______ is related to the volume of blood inside a blood vessel

capacitance

11

more blood in ______ blood tree than ______

venous (64%), arterial

12

Volume/Pressure =

compliance

13

if volume of vessel increases with only small changes in pressure that vessel is said to be _______

compliant

14

if small change in volume results in large change in pressure, vessel is

non-compliant

15

blood vessels vary widely in______

compliance-- based on vessel wall make-up

16

Veins have much less _______ and ______ than arteries in wall

elastin and smooth muscle

17

sympathetic activation of veinous smooth muscle (lower compliance) for purpose of

shifting blood to arterial system

18

veins have higher ability to change ________ over arteries

capacitance

19

nociceptive afferent fiber synapses on dorsal horn interneuron which synapses on ipsilateral ventral horn motor neurons which excite flexion and inhibit extension of limb (this is reciprocal innervation)

withdrawal reflex

20

decreased venous compliance =

decreased capacitance

21

for congestive heart failure

decrease amount of blood being delivered to heart by makeing veins more compliant w/ nitroglycerin, sodium nitropusside--increases veinous CAPACITANCE and COMPLIANCE

22

nitric oxide is a natural potent

vasodilator--to treat angina

23

the tension or stress in the wall of the LV during ejection

afterload

24

blood velocity slowest in ________ due to ___________

capillaries, large surface area

25

velocity is inversely proportional to ____

area

26

Velocity of blood flow =

flow/ cross sectional area

27

Blood flow Q =

pressure difference P / resistance R

28

more resistance =

less flow (vol/unit of time)

29

Q is inversely proportional to ____

resistance (ex. viscosity of fluid, length/width of vessel) Radius biggest player

30

resistance to blood flow

Poiseulle equation

31

resistance to flow types-- ________ and __________

series and parallel

32

series resistance

Rtotal = R1 + R2 + R3....

33

parallel resistance

1 / Rtotal = 1/R1 + 1/R2 + 1/R3....

34

more open capillary beds =

raise resistance

35

when fluid flows in parallel layers

laminar flow

36

when obstructions build up in vessels

non-laminar flow--makes noises

37

unusual sound blood makes as it rushes past obstruction

bruit

38

lowest pressure that occurs during cardiac cycle

diastolic pressure

39

systolic - diastolic pressure =

pulse pressure

40

volume of blood ejected from the one ventricle on a single cardiac cyclte (heartbeat)

stroke volume

41

volume of blood pumped by heart/ minute.

cardiac output

42

cardiac output =

stroke volume X heart rate

43

highest arterial pressure in cardiac cycle--

systolic pressure

44

systolic pressure happens ____-_______

mid-systole

45

diastolic pressure + 1/3 pulse pressure (estimates mean pressure)

mean arterial pressure

46

memorize mean pressures on outline

*

47

Pressure of aorta/ large arteries

100 mm Hg -- measured with catheter through internal jugular

48

arterioles pressure

50 mm Hg -- on exam numbers will be way off

49

capillary pressure

20 mm Hg

50

Vena cava pressure

4 mm Hg

51

Right atrium pressure

0-2 mm Hg

52

Pulmonary artery pressure

Sys-25 dia-8 mm Hg -- 15 mm Hg mean

53

pulmonary capillaries pressure

10 mm Hg

54

pulmonary vein pressure

8 mm Hg

55

left atrium pressure

2-5 mm Hg

56

the end diastolic PRESSURE that stretches the right or left ventricle of the heart to its greatest geometric dimensions under variable physiologic demand

ventricular preload

57

preload

end diastolic volume of ventricle--measure of optimal actin-myosin arrangement-- related to sarcomere length at end of distole

58

if BP is low and pressure is low it can be assumed that

preload is low and normal saline should be infused

59

RV pressure

15-30 mm Hg

60

LA pressure

6-12 mm Hg

61

dyastoli

ventricle relaxed

62

S1 sound

mitral valve closure

63

S2 sound

aorta/ pulmonic closure---may be split due to vast difference in pressure

64

S2 split

A2 -- aortic 1st (higher pressure)
P2 -- pulmonic 2nd

65

capacitance vessels

veins

66

specialized myocardial cells for purpose of generation and conduction of depolarization

nodes of heart--SAVe HIS KIN

67

EKG Depolarization of atria

P wave-- SA node

68

Holds SA node stimulation of brief period

AV node--for purpose of complete atrial contraction

69

Depolarization of ventricles

QRS complex--AV node

70

more free intracellular Ca =

stronger heart contraction

71

stimulates intracellular Ca release

Ca induced Ca release--extracellular Ca AP excitation

72

SA resting membrane potential

not stable--decays to threshold 60-100 times/sec --> QRS automatically
its automaticity establishes heart rate

73

sympathetic tone on SA node

make phase 4 steeper--faster heart rate--slide 31

74

parasympathetic activity on heart

make phase 4 flatter--slows heart rate-- slide 31

75

SA node arrest due to

parasympathetic NS tone-- slide 35

76

imp anticholinergic drug

atropine--parasympathetolytic

77

SA node intrinsic firing rate

70-80 BPM

78

AV node intrinsic firing rate

40-60 BPM

79

Bundle of His intrinsic firing rate

40 BPM

80

Purkinje fiber intrinsic firing rate

15-20 BPM

81

examples of when you'd see latent pacemakers "take over" driving heart rate

vagal tone and "heart blocker drugs"

82

Slow depolarization of phase 4 result of

"funny" inward Na+ current

83

"Funny" inward current turned on by

repolarization from the previous action potential--ensures another AP will follow

84

Dopamine's action on heart

speeds up heart rate by stimulating nerve release of norepi

85

If SA node not firing or firing at same time as AV node

"Junctional Rhythm"--no P wave--passive filling of ventricles--20% loss of Cardiac output

86

subunit of troponin

C, I, T -- looked for in blood after MI

87

allows small amount of Ca in to induce Ca release from sarcoplasmic reticulum

VOLTAGE GATED Ca channels

88

voltage change inducing voltage gated Ca channels to open from outside cell

mediated by Na and K as any other cell

89

STRENGTH of heart contraction directly related to

amount of FREE Ca within cell

90

as with skeletal muscle--cardiac muscle must be stretched to ideal length to get

optimal contraction

91

without atrial kick

loss 20% of cardiac output because myocardium not stretched to optimal level pre-systole

92

frank-starling law says

increasing dyastolic pressure raises cardiac output--up to a critical point at which too much stretch from pressure causes not enough actin-myosin (too much preload) overlap and lowers cardiac output

93

aortic pressure

after load

94

ventricular end diastolic muscle fiber length

ventricular preload

95

volume of blood ejected with each beat

stroke volume

96

% of blood in the ventricle at the end of diastole, ejected with a single beat

ejection fraction -- normally 55%

97

cardiac output

stroke volume X heart rate

98

with activity--heart contractility raises in stair step pattern due to

intracellular free Ca not pumped back into SR fast enough

99

Parasympathetic tone only affects

decrease contractility--atria only

100

sympathetic tone will

increase heart contractility--atria and ventricles

101

pickle lady

rapid spike of salt in cardiac system--water follows salt--congestion of blood in lungs because heart can't keep up. veinous backup will cause pt to cough up pink sputum. Overstretched heart, increased afterload because of raised resistance due to sympathetic tone on arteries, acedosis because of CO2 buildup, weakness due to bad blood profusion.

102

central venous pressure related to

left ventricular pressure--> LV volume --> LA pressure--> etc.

103

heart beats per munute

heart rate

104

preload =

ventricular preload

105

stretch of ventricle-- position on frank-starling curve--aka actin-myosin positoning

preload--ventricular end diastolic muscle fiber length--(related to ventricular end diastolic volume or pressure)

106

most important protein in blood contributing to oncotic pressure

serum albumin

107

pressure would raise steeply in LV if

muscle was non-compliant due to prolonged untreated ^ BP--> hypertrophy of muscle = less compliance

108

stroke volume X aortic pressure =

cardiac work

109

cardiac work directly correlated with

O2 consumption

110

volume work for heart MUCH easier than

pressure work

111

Frank-Starling relationship between

pressure and volume

112

Best way to treat ventricular hypertrophy is

make sure it never happens by treating ^BP--Beta blockers, Ca channel blockers--may get resistance from Pt's due to side effects

113

treat volume overload of heart with

diuretics

114

beta-blockers and CCBs

decrease CONTRACTILITY --> decrease myocardial O2 requiremnts --> circumvent angina

115

anti-anxiety drugs i.e. valium may help ^ BP or volume overload by

decreasing sympathetic tone--thereby decreasing myocardial O2 demands

116

arterial side
venous side

-hydrostatic pressure overpowers oncotic pressure--H2O out
-oncotic pressure overpowers hydrostatic--pulls water in

117

pickle lady

more solutes in blood pull water into blood --> ^ blood volume--> heart must work harder (might not be able to)

118

components of Starling forces

-capillary hydrostatic pressure (PUSHING pressure w/in cap)
-interstitial fluid hydrostatic pressure (pressure outside cap)
-oncotic pressure (PULLING pressure w/in cap)
-interstitial fluid osmotic pressure

119

alpha 1 adrenergic agonis

constrict ARTERIAL tree--fight or flight (pale w/ fear)

120

______ amount of capillary beds open at any time

small (10-20%) -- brain, heart, kidneys always open--sympathetic

121

parasympathetic NS innervates the

SA and AV nodes--> only atria

122

^ thoracic space --> decrease in pleural pressure

general gas law

123

difference in pressure across something (airway, lung wall, etc) "inside"-"outside" =

transmural pressure--general term (transplural P is subcat)

124

transplural pressure=alveolar pressure - pleural pressure

keeps lungs inflated 0 - (-5) = 5
-1 - (-7) = 6