Cardiovascular System - Lecture 7 Flashcards

1
Q

What kind of waves does the heart propagate?

A

un-damped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens to colliding waves of the heart?

A

they block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What was the phenomenon that Mines was exploiting in his experiment?

A

if you take a chunk of heart muscle out, you will have heterogeneity and some cells will have a slightly longer refractory period than other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many times does the heart beat per second?

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How long do the ventricles contract for during a heart beat?

A

1/3 of the period that the heart contracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the pressure of the ventricle (L or R) compared to the aorta initially when the heart beats?

A

it is lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When does the ventricle pressure stop increasing during a heart beat?

A

until it is greater than the aortic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens after the ventricular pressure stops increasing during a heart beat?

A

the aortic valve opens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens to the pressure in the ventricles after the aortic valve opens?

A

it drops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 5 steps after one of the ventricles beats?

A
  1. pressure in the ventricle is lower than the aorta
  2. pressure in the ventricle increases until it is greater than the aortic pressure
  3. aortic valve opens
  4. aortic pressure tracks ventricular pressure
  5. pressure in the ventricles starts to drop
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the mean arterial pressure equal to?

A

100 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the formula for mean arterial pressure?

A

MAP = diastolic pressure + 1/3 pulse pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why doesn’t the aortic pressure not drop to zero?

A

because of the Windkessel effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is compliance?

A

how easy it is to stretch out the muscular wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How much of the cycle do the ventricles contract?

A

1/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How much of the cycle is systole?

A

1/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How much of the cycle is diastole?

A

2/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How much of the cycle do the ventricles not generate pressure?

A

2/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why is the systemic pressure > 0?

A

due to the Windkessel effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the formula for compliance?

A

C = change in volume/change in pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does an aneroid sphygmomanometer measure?

A

the pressure in the cuff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does an aneroid sphygmomanometer consists of?

A

a cuff with a bladder
an inflating bulb
a needle valve
an aneroid gauge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the difference between an aneroid sphygmomanometer and a mercury sphygmomanometer?

A

it uses a column of mercury instead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 3 indirect ways to measure blood pressure?

A

palpation, auscultation, oscillometry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which artery are you reading the pulse from using the palpation method?

A

the radial artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What kind of pressure is found using palpation?

A

maximum systolic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the steps in measuring blood pressure using palpation?

A

1) Fill cuff until no pulse is detected
2) release pressure (needle valve) slowly
3) When you feel the pulse = Systolic BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What do you use to measure blood pressure in auscultation?

A

sounds using a stethoscope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are you listening for when using auscultation to measure BP?

A

Korotkoff sounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What happens to the laminar flow in arteries when blood pressure is taken using auscultation and the cuff deflates?

A

there is no sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Why does flow expansion result in turbulence during auscultation?

A

because there is a flow of blood from a compressed artery to an uncompressed artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What generates sound in auscultation?

A

turbulence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What causes tubulence?

A

the wirls when you let in a bit of blood from a compressed artery to an uncompressed artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What pressure is heard when you start to hear Korotkoff sounds?

A

systolic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

When do you stop hearing Korotkoff sounds?

A

when you have laminar flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What pressure is heard when you stop hearing Korotkoff sounds?

A

diastolic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What does the machine attached to the cuff sense during oscillometry?

A

senses the pressure inside the cuff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What does the machine send to the cuff during oscillometry?

A

pressure waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Why is blood pressure important?

A

because we need a pressure gradient on one side of the organ to the other so that blood flows through the capillary network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

The perfusion pressure of the arteries is much ___ than the perfusion pressure in the veins

A

larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is flow equal to?

A

MAP/R

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are the 3 ways we can regulate BP?

A

1) Adjust flow according to need (e.g. exercise)
2) Keep flow in organs constant despite fluctuations in ‘P’ (“autoregulation”) 3) Minimize fluctuations in Pa (neuro-hormonal control)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the total peripheral resitance equal to?

A

MAP/CO

44
Q

What is the cardiac output equal to?

A

HR (heart rate) x SV (stroke volume)

45
Q

How can we calculate MAP?

A

CO x TPR

46
Q

Why does the left ventricle generate a lot of pressure?

A

because it is very thick and it needs to overcome a large resistance in the systemic circulation

47
Q

Why does the right ventricle generate less pressure?

A

because it has a thin wall and needs to do less work to overcome the resistance of the pulmonary arm

48
Q

When we calculate the pulmonary vascular resistance (PVR), what must we take into account unlike MAP?

A

pulmonary vein pressure

49
Q

What is mean pulmonary artery pressure equal to?

A

15 mmHg

50
Q

What is pulmonary vein pressure equal to?

A

5 mmHg

51
Q

What is pulmonary perfusion pressure equal to?

A

10 mmHg

52
Q

Why is PVR«TPR?

A

because the flow to the lungs is equal to that of the systemic organs

53
Q

What kind of pressure and resistance does the systemic circulation have?

A

high pressure, high resistance circulatory system

54
Q

What kind of pressure and resistance does the pulmonary circulation have?

A

low pressure, low resistance circulatory system

55
Q

What happens to ventricles during ventricular systole?

A

they are contracting

56
Q

Are the AV valves and aortic/pulmonary valves open or closed during isovolumetric ventricular contraction?

A

closed

57
Q

Are the AV valves and aortic/pulmonary valves open or closed during ventricular ejection?

A

AV valves: closed
aortic and pulmonary valves: open

58
Q

What happens to the pressure in the ventricles during ventricular ejection?

A

it increases until the pressure in the ventricles is greater than the pressure in the pulmonary trunk and aorta

59
Q

Where does blood flow during ventricular ejection?

A

out of the ventricles

60
Q

What happens to ventricular contraction and pressure during isovolumetric ventricular relaxation?

A

ventricular contraction stops and pressure drops

61
Q

Are the AV valves and aortic/pulmonary valves open or closed during isovolumetric ventricular relaxation?

A

closed

62
Q

What happens to the pressure in the aorta and pulmonary trunk during isovolumetric ventricular relaxation?

A

it remains high due to the Windkessel effect

63
Q

What happens to the atria during isovolumetric ventricular relaxation?

A

they have been filling

64
Q

What happens to the pressure of the ventricles during isovolumetric ventricular relaxation?

A

it drops to almost 0

65
Q

Why do the AV valves open during ventricular filling?

A

because the pressure is lower in the ventricles than in the atria

66
Q

What do the atria do after the sinus node fires during ventricular filling?

A

they contract and push a little more blood into the ventricles

67
Q

Are the AV valves and aortic/pulmonary valves open or closed during ventricular filling?

A

AV valves: open
aortic and pulmonary valves: closed

68
Q

What are the 4 steps in the cardiac cycle?

A
  1. ventricular filling
  2. isovolumetric ventricular contraction
  3. ventricular ejection
  4. isolvolumetric ventricular relaxation
69
Q

Wiggers diagram shows phases for which side of the heart?

A

left heart

70
Q

Why does aortic pressure spike in Wiggers diagram?

A

due to ventricular contraction

71
Q

During the filling phase, the pressure in the left ventricle is slightly ___ than the left atria.

A

lower

72
Q

During the filling phase, is the mitral valve open or closed?

A

open

73
Q

What does the P-wave represent during the filling phase?

A

depolarization of the atria

74
Q

What happens to the atrial pressure during the P-wave?

A

it increases

75
Q

What happens to the AV valves during the P-wave?

A

they open

76
Q

Where does blood move when the AV valves open?

A

to the ventricles

77
Q

What happens to the ventricles during the QRS complex?

A

they are depolarized

78
Q

What happens to the pressure of the ventricles during the QRS complex?

A

they increase

79
Q

What happens to the volume of blood in the ventricles during isovolumetric ventricular contraction?

A

it remains the same

80
Q

What happens to all the valves when ventricles contract?

A

they close

81
Q

Why does the semilunar valve open?

A

to send blood to the aorta from the ventricle

82
Q

Why is the pressure in the ventricles greater than the aortic pressure during ventricular ejection?

A

because you need enough pressure in the ventricle to overcome the pressure in the aorta to push blood

83
Q

What happens to the ventricular volume once the blood in the ventricle is pushed out to the rest of the body?

A

it decreases

84
Q

What happens to the ventricle during the T-wave?

A

it repolarizes

85
Q

What happens to the ventricular pressure during the T-wave?

A

it decreases

86
Q

What happens to the valves during isovolumetric ventricular relaxation?

A

they close

87
Q

What happens to the pressure in the ventricles during isovolumetric ventricular relaxation?

A

it drops

88
Q

When does ventricular filling happen?

A

once ventricular pressure drops below atrial pressure

89
Q

What happens to the AV valve once the ventricular pressure drops below the atrial pressure?

A

it opens

90
Q

Where does the 1st heart sound happen?

A

at the QRS complex

91
Q

Why do we hear the first heart sound?

A

because the AV valve is closing due to the ventricles contracting

92
Q

When does the 2nd heart sound happen?

A

after the T-wave

93
Q

Why do we hear the second heart sound?

A

because the aortic valve is closing

94
Q

What happens to the right heart during the cardiac phases?

A

the same events as the left heart but with lower pressures

95
Q

What is stroke volume equal to?

A

120mL–50mL=70mL

96
Q

What is the formula for stroke volume?

A

end diastolic volume(EDV) – end systolic volume(ESV)

97
Q

What is the formula for ejection fraction?

A

stroke volume (SV) / end diastolic volume (EDV)

98
Q

What is ejection fraction equal to?

A

70 mL/120 mL = 0.6 or 60%

99
Q

What is the formula for cardiac output?

A

heart rate (HR) x stroke volume (SV)

100
Q

What is cardiac output equal to?

A

70 b/min x 70 ml = 4900 mL min (5L / min)

101
Q

(T or F) The ventricle generates pressure over the duration of the cardiac cycle

A

False! - it only generates pressure over about 1/3 of the cycle. The rest is due to the Windkessel effect

102
Q

(T or F) The Windkessel effect generates pressure over the cardiac cycle except during the contraction of the ventricle.

A

False! Systole starts the instant that the ventricle contracts. There is a period of isovolumetric ventricular contraction when the aortic valve is closed, and no pressure is generated by the ventricle in the aorta.

103
Q

(T or F) The BP measures of palpation, auscultation and oscillometry measure the same thing in different ways.

A

False! While they all can estimate systolic pressure, only auscultation and oscillometry measure diastolic pressure.

104
Q

(T or F) A patient has a muscle twitch in their bicep. This might give abnormal readings using an automated BP machine, but not using the stethoscope method.

A

True! The cuff pressure in the oscillometry measure is used to estimate BP. Twitches in the muscle would change the cuff pressure, but wouldn’t affect the Korotkoff sounds, which are downstream. But this is just a guess! – the manufacturers probably have algorithms in place to counter this.

105
Q

The two valves of the left ventricle are either open or closed. There are 4 possible ways the valves can present: (closed, closed), (open, closed), (closed, open) or (open, open), and each defines a phase. Is this true?

A

False! The two valves are never open at the same time. Blood would flow in the wrong direction!