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Flashcards in CVS 3 Deck (103)
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1
Q

CO of left heart=

A

co of right heart

2
Q

left sided CO is

A

systemic blood flow

3
Q

right sided CO is

A

pulmonary blood flow

4
Q

what carries blood away from the heart

A

arteries

5
Q

____ are under high pressure

A

arteries

6
Q

the blood volume contained in arteries is called

A

stress volume

7
Q

arteries are thick walled with what type of tissue and muscle

A

elastic tissue and smooth muscle

8
Q

what is the smallest branches of the artieries

A

arterioles

9
Q

where is the highest resistance in CVS

A

the arterioles

10
Q

what controls the arterioles resistance

A

autonomic nervous system

11
Q

alpha 1 adrenergic receptors are found on the arterioles of which 3 areas

A

skin, renal and splanchnic circulation

12
Q

beta 2 adrenergic receptors are found on the arterioles of the___

A

skeletal muscles

13
Q

what has the largest total cross-sectional and surface area

A

capillaries

14
Q

capillaries are the site of exchange for what three things

A

nutrients water and gases

15
Q

what consist of a single layer of endothelial cells

A

capillaries

16
Q

what are venules

A

formed from merged capillaries

17
Q

what carries blood toward the heart

A

veins

18
Q

veins progressively merge to form

A

larger veins

19
Q

what is the pressure for veins

A

low pressure

20
Q

veins are ___ walled, no ____ tissue

A

thin

elastic

21
Q

what innervates the veins

A

autonomic nervous system (alpha 1)

22
Q

which receptor innervates the veins

A

alpha 1 adrenergic receptor

23
Q

the blood volume contained in veins is called___

A

unstressed volume

24
Q

veins contain what proportion of blood in the CVS

A
HIGHEST PROPORTION (65%)
reservoir function
25
Q

hematocrit normal person

A

40-45%

26
Q

hematocrit anemia person

A

10-20%

27
Q

hematocrit polycythemia

increase crit increase viscosity=

A

60-70%

decreased flow rate

28
Q

the percentage of blood that is cells (RBC, WBC, Platelets) is called

A

hematocrit

29
Q

what three conditions increase blood viscosity

A

polycythemia

multiple myeloma

hereditary spherocytosis

30
Q

V=

v=velocity

A

Q/A
Q=blood flow
A= cross sectional area

31
Q

velocity is directly proportional to

inversely proportional to

A

proportional to blood flow

inversely proportional to cross sectional area

32
Q
velocity as described greatest to least in 
capillaries
small veins
arterioles 
aorta
A

aorta
arterioles
small veins
capillaries

33
Q

blood flow Q=

A

change P/R
change P= pressure difference between two ends of vessel
R= resistance

34
Q

what is blood flow inversely proportional to

A

Blood flow is inversely proportional to the resistance of blood vessels

35
Q

increased resistance=

A

decrease blood flow

36
Q

decreased resistance

A

increased blood flow

37
Q

circulation of an adult is how many liters/min

A

Overall flow in the circulation of an adult is 5 liters/min which is the cardiac output

38
Q

co=

A

svXhr

39
Q

mean arterial pressure=

A

co X TPR

40
Q

map =

A

diastolic + 1/3 pulse pressure

41
Q

pulse pressure=

A

systolic- diastolic

42
Q

if the HR is too high what is diastolic filling and CO

A

diastolic filling is incomplete and CO drops

43
Q

Causes of turbulent blood flow:

A

high velocities

sharp turns in the circulation
rough surfaces in the
circulation
rapid narrowing of blood vessels

44
Q

Turbulence is increased by

A

decreased blood viscosity

increase blood velocity

45
Q

SVR=

A

map-cap/COx80

46
Q

MAP=

A

COxSVR/80+CVP

47
Q

laminar flow - where is the highest velocity

A

in the middle

48
Q

what does capacitance (compliance) describe

A

the distensibility of the blood vessels

49
Q

vascular complicance=

A

volume/pressure

50
Q

compliance- is it greater in the veins or arteries

A

veins

51
Q

what is the result of capacitance with increasing age

A

capacitance decreases with age- in old age the arteries becomes stiffer and less distensible

52
Q

capacitance is inversely related to

A

elastance or stiffness.

the greater the elastic tissue in blood vessel- higher elastance=lower compliance

53
Q

when venous compliance decreases the stress volume

A

increase- due to shifting of blood from veins to arteries.

54
Q

where is capacitance highest

A

in the vein

55
Q

where is capacitance low

A

artery

56
Q

where is capacitance lowest

A

artery (aging)

57
Q

the force exerted by blood against per unit area of vessel wall

A

blood pressure

58
Q

where does the largest decrease in pressure occur

A

across the arterioles because they are the site of highest resistance.

59
Q

pressure is highest in the ___

pressure is lowest in the ___

A

highest in the aorta

lowest in the venue cavae

60
Q

as blood flows through the systemic circulation, pressure decreases progressively because of what

A

resistance to blood flow

61
Q

aorta pressure

A

100

62
Q

arterioles pressure

A

50

63
Q

capillaries pressure

A

20

64
Q

vena cava pressure

A

4

65
Q

is pulsatile
is not constant during cardiac cycle
what is this?

A

arterial pressure

66
Q

what is the highest arterial pressure during a cardiac cycle

A

systolic pressure (120)

67
Q

when is systolic pressure measured

A

after heart contracts and blood is ejected into the arterial system

68
Q

the lowest arterial pressure during a cardia cycle

A

diastolic pressure (80)

69
Q

when is diastolic pressure measured

A

when the heart is relaxed and blood is returning to the heart via veins

70
Q

what is the difference between systolic and diastolic pressures

A

pulse pressure

71
Q

when capacitance is decrease with aging what happens to the pulse pressure

A

increased pulse pressure

72
Q

the most important determinant of pulse pressure is stroke volume
increase stroke volume does what to pulse pressure

A

increase it

decreasing sv decreases pulse pressure

73
Q

Mean Arterial pressure

A

Is the average arterial pressure with respect to time

Can be calculated approximately as diastolic pressure plus on-third of pulse pressure

74
Q

venous pressure

A

The veins have a high capacitance and , therefore, can hold large volumes of blood at low pressure

75
Q

Atrial Pressure

A

Left atrial pressure is estimated by the pulmonary capillary wedge pressure (PCWP). A catheter (Swan- Ganz) , inserted into the smallest branches of the pulmonary artery, makes almost direct contact with the pulmonary capillaries. The measured pulmonary capillary pressure is slightly higher than the left atrial pressure

76
Q

atrial pressure- pressure measurements

A

Its an indirect measurement of left ventricular performance

77
Q

a wave

A

atrial contraction . Absent in atrial fib. Enlarge in pulmonary hypertension

78
Q

c’ wave

A

RV contraction (tricuspid valve bulging into atrium)

79
Q

v wave

A

atrial pressure due to filling against closed tricuspid valve. Enlarged in tricuspid regurgitation

80
Q

‘x’ descent:

A

atrial relaxation + RV contraction (pulls atrium downward)

81
Q

y’ descent:

A

emptying of right atrium after tricuspid valve opens

82
Q

Cannon wave

A

large wave not corresponding to a , v or c wave. Due to complete heart block or junctional arrhythmias.

83
Q

cvp reflects

how do we guide fluid replacement

A

CVP reflects right ventricular preload

Guide during intravenous fluid replacement

84
Q

Anal veins

A

Hemorrhoids

85
Q

varicose veins.

A

Faulty venous valves lead to

86
Q

venous pump-

A

The venous valves and pump maintain a relatively low venous pressure in the legs.

87
Q

what is important in the transport of nutrients to tissues

A

microcirculation

88
Q

where is the site of waste product removal

A

micorcirculation

89
Q

in microcirculation, with over 10billion capillaries with a surface area of 500-700 square meters- what is their function

A

perform solute and fluid exchange

90
Q

the blood flow through the capillaries is regulated by what

A

contraction and relaxation of the arterioles and the precapillary sphinters

91
Q

what is composed of unicellular layer of endothelial cells surrounded by a basement membrane

A

capillary wall

92
Q

how does solute and water move across the capillary wall

A

via the intercellular cleft (space between cells)

93
Q

the most important means by which substances are transferred between plasma and interstitial fluid is by____

A

simple diffusion

94
Q

what diffuses directly through cell membrane of capillaries

A

lipid soluble substances (co2, o2)

95
Q

how does water soluble substance move across the capillary wall

A

intercellular clefts

96
Q

what enhances diffusion across capillary membranes

A

concentration differences/

concentration gradient

97
Q

capillaries in different tissues have what distinction in their permeabilities

A

extreme differences

98
Q

what is the description of the intracellular cleft in the brain

A

its exceptionally tight (BLOOD BRAIN BARRIER)

99
Q

what is the description of intracellular clefts in the liver and intestine

A

exceptionally wide

100
Q

why are they intracellular clefts in the liver and intestine very wide

A

to allow passage of protein

101
Q

what are the capillaries in the liver and intestine called

A

sinusoids

102
Q

the space between cells is called_____

the fluid in this space is called____

A

interstitial

interstitial fluid

103
Q

almost all fluid in interstitium is in form of ___

A

gel (fluid proteoglycan)