Physiology- Cardio Flashcards Preview

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Flashcards in Physiology- Cardio Deck (102)
1

What are the 3 main plasma proteins?

Albumin
Globulins
Fibrinogen

2

What is the major blood electrolyte?

sodium

3

Where does erythropoiesis occur?

bone marrow

4

Cessation of bleeding is known as what?

hemostasis

5

What is the role of platelets in hemostasis?

they stick to the injured site causing a platelet plug

6

What do you call a clot that includes RBCs?

a thrombus

7

What makes up a clot?

platelet plug plus fibrin

8

Vitamin K is important for which clotting factors?

II, VII, IX, X

9

What initiates the intrinsic pathway of the blood coagulation cascade?

blood coming into contact with exposed collagen of the damaged tissues.

10

What mineral is needed for proper clotting?

calcium

11

What is the insoluble substance that precipitates out at an injury site?

fibrin

12

Hemophilia is a genetic absence of what clotting factors?

Hemophilia A: Factor VIII
Hemophilia B: Factor IX

13

What substance dissolves clots?

Plasmin

14

What substance cleaves fibrinogen into fibrin?

Thrombin

15

Myocardial cells have more of this organelle due to its high oxidative capacity:

mitochondria

16

What cellular feature allows the heart to contract as a syncytium?

gap junctions between the muscle cells

17

How do T tubules differ between cardia and skeletal muscle?

Cardiac: T tubules contain extracellular fluid high in calcium
Skeletal: T- tubules contain extracellular fluid that is low in calcium

18

What structure brings depolarization inside the cardiac muscle and helps regulate cytoplasmic calcium?

t tubules

19

What prevents tetanic contraction in cardiac muscle?

the long cardiac action potential

20

What aspect of the action potential prevents a second action potential from taking place?

long refractory period of plateau period

21

What is the originator of the cardiac action potential?

the SA node

22

What property allows the SA node to function as a primary pacemaker?

small cell size allows it to spontaneously depolarize

23

What acts as a delay station for the action potential?

The AV node

24

Why does the AV node delay the action potential?

to allow atrial muscle to depolarize before ventricular muscle, to allow for filling

25

What can act as a secondary pacemaker in pathological conditions?

the AV node

26

What allows for rapid conduction of the action potential?

Bundle of His
Bundle Branch fibers
Purkinjie fibers
Specialized tracts

27

What is the sequence of electrical impulse in the heart?

SA node--> specialized tracts--> AV node and atrial muscle--> Bundle of HIS--> bundle branches--> Purkinjie fibers--> ventricular muscle

28

What serves to depress the heart rate at rest by slowing down the SA node?

parasympathetic nervous system

29

How does the sympathetic nervous system affect conduction through the electrical system?

it speeds up conduction of the action potential and therefore increases heart rate

30

What nerve has the greatest influence on the heart?

the vagus nerve

31

What is the affect of vagal stimulation on the heart?

It serves to slow the conduction of action potentials through the AV node due to the parasympathetic nerve fibers

32

How does norepi affect heart contractility?

it increases heart contractility

33

In which phase do the ventricle fill?

late diastole

34

In which phase do we get isovolumetric contraction?

early systole

35

What phase of the cardiac cycle uses up the most energy?

the isovolumetric contraction of early systole

36

What is the purpose of isovolumetric contraction?

to build up the pressure so as to overcome the high aortic pressure

37

In which phase is ejection?

late systole

38

When is the relaxation phase?

early diastole

39

What causes heart sound 1?

closing of atrioventricular valves (mitral and tricuspid)

40

What causes heart sound 2?

closing of pulmonic and aortic valves

41

When in the cycle is S1?

late diastole/early systole

42

When in the cycle is S2?

end systole/ early diastole

43

What records electrical activity of the heart?

EKG

44

What information do we get from an EKG?

heart rate, rhythm, axis of the heart

45

What on an EKG marks atrial depolarization?

P wave

46

What on an EKG marks ventricular depolarization?

QRS complex

47

What on an EKG marks ventricular depolarization?

T wave

48

What 2 things influence cardiac output?

heart rate and stroke volume

49

How does the heart adapt to hypertension?

increases wall thickness--> cardiac hypertrophy
cardiac dilation

50

What are the 3 major substrates for cardiac metabolism?

fatty acids, glucose, glycogen breakdown

51

What are 3 minor substrates for cardiac metabolism?

Lactic acid, ketones, intramuscular triglycerides

52

What is the major limitation of energy metabolism by myocardium?

coronary blood flow delivering oxygen

53

What 2 factors determine oxygen consumption by the myocardium?

1. wall tension in the heart that must be overcome e.g. during isovolumetric contraction
2. Isotonic contraction to eject the blood

54

What property of blood vessels helps push blood through the arteriole system?

elastic tissue

55

What property of blood vessels does smooth muscle provide?

its ability to contract and dilate allows blood to be shunted from one area to another

56

What protects blood vessels against distension?

the fibrous nature of the tissue

57

What type of circulation has few controls, and is a low pressure/low resistance system?

pulmonary circulation

58

What serves as a conduit for blood?

arteries

59

What types of blood vessels are resistance vessels due to their smooth muscle?

arteries and arterioles

60

What blood vessel in involved in nutrient and waste exchange?

capillaries

61

What type of capillary excludes proteins and cells from passing through?

Continuous capillaries

62

What type of capillary excludes cells? Where are they found?

fenestrated capillaries, found in the kidney

63

What type of capillary allows cells and protein to pass through? Where are they found?

sinusoidal/ discontinuous
found in liver, bone marrow, spleen

64

What blood vessels act as capacitance vessels?

veins and venules

65

What increases venous return?

vasoconstriction

66

Which blood vessels have valves?

veins and venules

67

What are the 4 pressures that affect capillary exchange?

1. plasma oncotic pressure
2. plasma hydrostatic pressure
3. interstitial oncotic pressure
4. interstitial hydrostatic pressure

68

Which of the 4 capillary pressures favors filtration?

1. plasma hydrostatic pressure
2. Interstitial hydrostatic and oncotic pressure

69

Which of the 4 capillary pressures is actually a negative pressure or "suction"?

interstitial hydrostatic pressure

70

What are 3 mechanisms for edema?

1. increased plasma interstitial pressure
2. decreased plasma oncotic pressure
3. increased interstitial oncotic pressure

71

How will decreased blood protein synthesis cause edema?

by decreasing plasma oncotic pressure

72

What will influence lymph flow?

smooth muscle tone
skeletal muscle contraction

73

Pressure in the right atrium or the vena cava at the level of the heart is known as what?

central venous pressure

74

What will increase venous blood flow and decreased venous pressure?

skeletal muscle contraction

75

Where are baroreceptors located?

aortic arch and carotids

76

What do baroreceptors sense?

blood pressure

77

What kind of neurotransmitters are released when baroreceptors are stimulated by high blood pressure?

inhibitory neurotransmitters

78

What do inhibitory neurotransmitters accomplish with relation to blood pressure?

decrease in sympathetic firing that innervate smooth muscle, causing vasodilation

79

What is accomplished by stimulation of baroreceptors?

decrease in blood pressure due to the vasodilation

80

Where are chemoreceptors located?

aortic arch and carotids

81

What are chemoreceptors sensitive to?

low blood oxygen levels as a result of decreased blood flow due to low blood pressure

82

What kind of neurotransmitter is released when chemoreceptors are stimulated by low blood pressure?

excitatory neurotransmitters

83

What to excitatory neurotransmitters do with relation to blood pressure?

increase sympathetic firing down neurons that innervate smooth muscle of blood vessels --> vasoconstriction

84

What is accomplished by the stimulation of chemoreceptors?

an increase in blood pressure by vasoconstriction

85

How does increased vagal output cause a decreased blood pressure?

via its parasympathetic effects that cause decreased heart rate --> decreased CO--> decreased BP

86

How does the kidney affect blood pressure?

via the renin angiotensin system: dec BP --> dec GFR--> renin released--> aldosterone release --> kidneys reabsorb Na and water--> increase in blood volume --> increased BP

87

How doe ADH affect blood pressure?

low BP --> ADH release--> kidney holds onto water--> increased blood volume --> inc BP

88

In metabolic control of blood flow, decreased oxygen causes release of metabolite (CO2, lactate etc.) which causes what?

vasodilation of blood vessels, metabolic acidosis

89

what is the name of the control that protects against high blood pressure damage?

autoregulation

90

What tissue is best at auto regulation?

the brain

91

What is the net result of blood vessels on auto regulation?

vasoconstriction

92

What is the long term control of blood flow called (ie. compensation for some type of tissue ischemia)

angiogenesis

93

What is the primary catecholamine for alpha adrenergic receptors?

norepinephrine

94

Which vascular beds have primarily alpha receptors?

skin, renal, splanchnic vasculature

95

What affect does Norepi have on smooth muscle cells in the vascular beds?

vasoconstriction

96

What is the primary catecholamine for beta 2 receptors?

epinephrine

97

Which vascular beds have primarily beta 2 receptors?

coronary and skeletal muscle vessels

98

What affect does epic have on smooth muscle in the vascular beds?

vasodilation

99

Which of the ANS branches has the most control over circulation?

sympathetics via norepi/epi

100

Which vascular beds are over perfused at rest?

skin, splanchnic and renal

101

Brain ischemia caused by and increase in CSF pressure is known as what?

Cushings reflex

102

When, during the cardiac cycle, are the coronary arteries perfused?

during diastole