Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Hypertension RCM week 6 > Vascular control > Flashcards

Vascular control Flashcards

1
Q

What is the most important factor determining resistance

A

Arteriolar diameter

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

What is blood vessel radius dependent on

A
  • Active tension exerted by smooth muscle (vascular smooth muscle)
  • Passive elastic properties of wall (elastin and collagen)
  • Blood pressure inside vessel (tissue pressure outside vessel-veins)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Is wall tension greater in small vessels or large vessels

A

Smaller in small vessels

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

What increases wall tension

A

Increase in radius (eg aneurysm)

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

What can develop active tension

A

Smooth muscle

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

What does active control of vessel calibre allow

A
  • redistribution of blood flow
  • Control of pre/post capillary sphincters
  • Regulation of vascular tone and control of blood pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is vascular tone

A

Degree of constriction/dilatation

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

What is passive tension like and active tension like in a vasoconstrictor blood vessel

A
  • Increased active tension

- Decreases passive tension

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

What is active tension and passive tension like in a vasodilator blood vessel

A

Decreased active tension and increased passive tension

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

What is vasomotor tone

A

The degree of tension of the smooth muscle within the walls of blood vessels (especially arterials)

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

What is venomotor tone

A

The degree of tension in the muscle coat of a vein that determines the shape of the vein

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

What can constriction of blood vessels do

A

redistribute the blood flow by changing the active properties of the smooth muscle cells (ie in exercise). Allows us to distribute blood flow to specific parts of the body where it is most metabolically active

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

Mechanism of vasoconstriction

A

1) varicosities contain neurotransmitters. There is an influx of calcium in the varicosity. This makes vesicles fuse with the membrane
2) Vesicles release noradrenaline
3) noradrenaline acts on alpha 1 adrenoceptor receptors on smooth muscle cells and cause vasoconstriction

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

Where is noradrenaline released from

A

Sympathetic nerves

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

What does noradrenaline act on

A

Alpha 1, alpha 2, and beta 2

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

What do the noradrenaline acting on alpha 1 and 2 adrenoceptors do

A

Cause vasoconstriction

17
Q

What does noradrenaline acting on beta 2 adrenoceptors do

A

cause vasodilation

18
Q

What hormones cause constriction

A

Noradrenaline and adrenaline, vasopressin and angiotensin

19
Q

What hormones cause dilation

A

Noradrenaline, adrenaline, bradykinin

20
Q

Mostly, what do adrenoceptors do

A

Cause vasoconstriction in most vascular beds

21
Q

What are endothelium-derived vasorelaxants

A

Prostacyclin
Nitric oxide
Endothelium-derived hyperpolarising factor

22
Q

What are endothelium derived vasoconstrictors

A

Endothelin

23
Q

What does an increase in lactate cause in relation to smooth muscle contraction

A

Increase H+, increase in K+ and increase in adenosine causes dilatation

24
Q

In systemic vasculature, what does an increase in O2 and a decrease in Co2 cause

A

Constriction

25
Q

in systemic vasculature, what does an increase in Co2 and a decrease in O2 cause

A

Dilatation

26
Q

In pulmonary vasculature, what does an increase in Co2 and a decrease in O2 cause

A

Constriction

27
Q

In pulmonary vasculature, what does an increase in O2 and a decrease in Co2 cause

A

Dilatation

28
Q

What is blood flow like in the brain

A

Autoregulated (it is constant) therefore there is no change in flow

29
Q

What happens when there is an increase in pressure in the cerebral blood vessels

A

Blood vessels are stretched, and this causes vasoconstriction

30
Q

What happens in the brain if blood pressure falls

A

Less stretch on cerebral blood vessels therefore they vasodilate. The driving force has decreased so there is an overall same blood flow

31
Q

What mechanisms are primarily concerned with meeting blood flow demands of particular organs/tissues

A

Intrinsic mechanisms (metabolic, myogenic)

32
Q

What mechanisms are primarily concerned with regulation of arterial blood pressure

A

Extrinsic contort mechanisms (nerves, hormones)

33
Q

How much cardiac output does the Brain receive at rest

A

14%

34
Q

What causes vasodilation in the brain

A

H+, K+, adenosine, hypercapnia (too much CO2), and hypoxia (not enough oxygen)

35
Q

What is an important vasoconstrictor in pathological states (eg subarachnoid haemorrhage) in the brain

A

Endothelin

Hypertension RCM week 6 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions