Lecture 25 - Hypertension I Flashcards

1
Q

What does hypertension relate to?

A

Hypertension relates to high BP, specifically arterial blood presure.

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

What is pulse pressure?

A

Difference between systolic and diastolic pressure

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

How can we find MAP from SAP and DAP?

A

MAP= DAP +1/3(SAP-DAP)

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

What is SAP and DAP in normal arterial pressure?

A

SAP<120 and DAP<80

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

What is SAP and DAP in elevated arterial pressure?

A

SAP=120-129 and DAP<80

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

What is the SAP or DAP in Stage I Hypertension?

A

SAP=130-139 or DAP=80-89
Dont need both to have hypertension

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

What is the SAP or DAP in Stage II Hypertension?

A

SAP>140 or DAP>90
Dont need both to have hypertension

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

What happens to the physical factors of MAP during hypertension?

A

Arterial blood volume increase
Arterial compliance decrease

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

What regulates arterial blood volume long-term?

A

Kidney

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

What is arteriosclerosis?

A

Disease of media which alters stiffness
Media thickening in large or resistance arteries
Increasing stiffness of the arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is atherosclerosis?

A

Disease of the intima which alters conduit
Changes of the intima
Blockage of the arteries

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

What does increases in blood volume measure?

A

Vessel compliance. Increase of volumes is a measure of compliance, as vessel compliance decreases, so does the increase/change in volume.

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

Why does vessel compliance decrease with age?

A

Structure remodelling of the arterial wall

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

What are the changes in the vessel wall due to age?

A

Less elastin, more collagen, different type and more crosslinking
Collagen 1000x stiffer than elastin

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

Why does peripheral vascular resistance increase with age?

A

Because there is a decrease in arterial compliance

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

What does the increased peripheral vascular resistance do to BP?

A

Increase SAP and DAP

17
Q

What increases more, SAP or DAP, when there is an increase in peripheral vascular resistance and why?

A

An increase in peripheral vascular resistance will elevate systolic pressure more than diastolic pressure
At higher pressures (systole) the arteries are stiffer (less compliant) than at diastole (vessels are less stiff, more compliant).

18
Q

Why does arteriosclerosis cause hypertension?

A

Because arteriosclerosis alters media stiffness, which makes the vessel less compliant, thus increasing BP

19
Q

In systole, what is the flow wave generated by?

A

The heart

20
Q

In diastole, what maintains capillary flow?

A

In diastole, recoil of aorta maintains capillary flow

21
Q

What is flow wave?

A

Flow wave – blood flow caused by ejection of the heart which runs through the vasculature

22
Q

What does the distensibility of the act aorta as?

A

Storage of stroke volume in conduit vessels

23
Q

What is the flow of blood throughout the body?

A

Pulsatile flow into the aorta, but continuous/constant flow through the capillaries

24
Q

What is essential for dampening the pulsatile flow wave of the heart?

A

Compliance of the aorta

25
Q

What happens to flow waves as we age/in hypertension?

A

Stiff/rigid aorta – limited or almost no storage of stroke volume
During systole, aorta and capillary flow are high 24
During diastole, capillary flow decreases
Capillary flow is now pulsatile – less O2 nutrients exchange

26
Q

During systemic hypertension, the compliance of the aorta:
A. decreases, which decreases the pulsatility of blood flow through the capillaries.
B. decreases, which increases the pulsatility of blood flow through the capillaries.
C. increases, which decreases the pulsatility of blood flow through the capillaries.
D. increases, which increases the pulsatility of blood flow through the capillaries.

A

B. decreases, which increases the pulsatility of blood flow through the capillaries.

27
Q

What is pulse wave?

A

pressure wave caused by contraction of the heart which runs over the vasculature

28
Q

What is flow wave?

A

blood flow caused by ejection of the heart which runs through the vasculature

29
Q

What is the speed of pulse wave?

A

3-12 m/s

30
Q

What is the speed of pulse wave?

A

200-0 cm/s

31
Q

What is the observed pulse wave?

A

The observed pulse wave is created by a reflection of waves - forward, reflected
Reflection waves form at bifurcation

32
Q

What has a bigger contribution of reflections of pulse wave and why?

A

Distal vessels
Distal vessels are stiffer (faster pulse wave) they have larger contribution of reflections compared to proximal vessels

33
Q

Where does pulse wave travel faster?

A

Pulse wave travels faster in distal than proximal vessels
Aorta 3-5 m/s Radial artery 5-12 m/s

34
Q

Why does pulse wave increase as we age?

A

Reduced compliance of conduit arteries increases pulse wave velocity

35
Q

Where do reflection waves form?

A

At bifurcations

36
Q

Why does pulse wave contribute to coronary perfusion when young?

A

Reflected wave reach heart after closure of aortic valves (contributing to coronary perfusion)

37
Q

Why does pulse wave contribute to afterload when old?

A

Reflected waves reach heart before closure of aortic valves, increasing systolic blood pressure (afterload)

38
Q

The pulse wave velocity of the aorta decreases with older age BECAUSE at older age remodelling of the arterial wall results in a faster reflected pulse wave.
A. Both statements are correct and causally related.
B. Both statements are correct and NOT causally related.
C. Only the first statement is correct and the second statement is incorrect.
D. Only the second statement is correct and the first statement is incorrect.
E. Both statements are incorrect.

A

D. Only the second statement is correct and the first statement is incorrect.

39
Q

Where does peripheral resistance mostly reside?

A

Smaller arteries