Brainscape's Knowledge GenomeTM

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


See full index

Physiology 1 > Nervous And Hormonal Control Of Vascular Tone > Flashcards

Nervous And Hormonal Control Of Vascular Tone Flashcards

1
Q

What are the local controls of vascular tone?

A

Myogenic responses, paracrine and autocrine and physical factors (temp/shear stress)

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

What are the extrinsic controls of vascular tone?

A

Parasympathetic, sympathetic and sensory vasodilator nerves, sympathetic vasoconstrictor nerves, adrenaline, angiotensin II, vasopressin and atrial natriuretic peptide

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

What does paracrine affect?

A

Things very close to the source

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

What does autocrine mean?

A

A cell producing a substance that affects itself

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

How does local control of vascular tone work?

A

Regulates local blood flow to organs/tissues and is important for regional hyperaemia.
Vasodilators are used

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

What does extrinsic vessel control regulate?

A

Total peripheral resistance to control blood pressure. The brain selectively alters blood flow to veins according to need

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

What causes extrinsic control in nerves?

A

Vasoconstrictors like noradrenaline

Vasodilators like acetylcholine and nitric oxide

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

What hormones cause extrinsic control in blood vessels?

A

Vasoconstrictors like adrenaline and angiotensin I

Vasodilators like anti-natriuretic peptide

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

What is the pathway for the sympathetic vasoconstrictor system from the brain to the sympathetic ganglia?

A

Signal comes from the medulla oblongata down the main excitatory drive. Splits at the thoracic (T1-L2) spinal cord and either goes down a sympathetic preganglionic fibre or into the adrenal medulla

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

What do varicosities contain?

A
  • angiotensin II that act is on AT1 receptors to increase noradrenaline
  • metabolites prevent vasoconstriction to maintain blood flow
  • noradrenaline can also negatively feedback itself via alpha 2 receptors to limit its own release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are sympathetic vasoconstrictor nerves controlled by?

A

The brainstem

The rostral ventrolateral medulla is controlled by other areas like the caudal ventrolateral medulla and hypothalamus

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

What does tonic mean?

A

One action potential per second

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

What activity sets vascular tone?

A

Tonic sympathetic activity

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

What are the main roles of sympathetic vasoconstrictor nerves?

A
  • Distance sympathetic pathways innervate different tissue
  • precapillary vasoconstriction
  • control resistance arterioles
  • controls venous blood volume
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does pre capillary vasoconstriction lead to?

A

Downstream capillary pressure drop so increased absorption of interstitial fluid into blood plasma to maintain blood volume

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

How do control resistance arterioles work?

A

Allowing vasodilation to occur and controlling total peripheral resistance

Maintains arterial blood pressure and blood flow to the brain, myocardium and kidneys

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

How does control of venous blood volume work?

A

Venoconstriction leads to decreased venous blood volume increasing venous return. This increases stroke volume via starlings law

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

How does vasodilation normally occur?

A

By an inhibition of the sympathetic vasoconstrictor nerves

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

What type of tissues contain vasodilator nerves?

A

Tissues that have a specific function controlling a specific vascular bed

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

What part of the nervous system do vasodilator nerves generally belong to?

A

Parasympathetic

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

What happens when blood vessels are innervated by parasympathetic cholinergic fibres?

A

Release acetylcholine which then binds to muscarinic receptors on the smooth muscle and/or endothelium

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

What can M3 receptors on the vascular endothelium be coupled to?

A

The formation of nitric oxide which causes vasodilation

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

What type of receptor vasodilates in response to ACh?

A

M5 muscarinic

24
Q

What is an example of a sympathetic vasodilator nerve?

A

Skin (sudomotor fibres)

25
Q

How do the sudomotor fibres work?

A

Release ACh and vasoactive intestinal peptide, causing vasodilation via NO associated routes

26
Q

What does increased blood flow cause in the skin?

A

More sweat and allows heat loss

27
Q

What has some control over the sudomotor fibres in the head, face and upper chest and what do they cause?

A

Emotional centres are involved in blushing

28
Q

What glands release ACh and vasoactive intestinal peptide?

A

Salivary glands

29
Q

What releases just vasoactive intestinal peptide?

A

The pancreas and intestinal mucosa

30
Q

What do male genitalia release for vasodilation?

A

NO

31
Q

How does vasodilation work in male genitalia?

A

NO causes production of cGMP which leads to vasodilation .

32
Q

How does sildenafil (viagra) work?

A

Inhibits the breakdown of cGMP by phosphodiesterase 5

33
Q

What are sensory vasodilator fibres (nociceptive C fibres) involved in?

A

Stimulation of sensory axon reflex by trauma or infection etc

34
Q

What do nociceptive C fibres cause release of?

A

Substance P or calcitonin gene- related peptide (CGRP)

35
Q

What do nociceptive C fibres act on?

A

Mast cells to release histamine or the endothelial and vascular smooth muscle

36
Q

What are the three things in the Lewis triple response?

A

Local redness, wheal and flare

37
Q

How does the Lewis triple response work?

A

When there is trauma, an action potential will be sent to both the dorsal root ganglion and down the axon collateral. The axon collateral then causes release of substance P and mast cell degranulation

38
Q

What are the hormonal vasoconstrictors?

A

Adrenaline, angiotensin II and vasopressin

39
Q

What are the hormonal vasodilators?

A

Atrial natriuretic peptide, insulin, estrogen, relaxin

40
Q

When is adrenaline released?

A

During exercise and fight or flight response

Hypotension and hypoglycaemia

41
Q

What are the main roles of adrenaline?

A

Glucose mobilisation, stimulation of heart rate and contractility during normal exercise and as a vasodilator of coronary and skeletal muscle arteries

42
Q

What does adrenaline do in most tissues (and with what receptor)?

A

Vasoconstrict alpha 1

43
Q

What does noradrenaline do in most tissues (and with what receptor)?

A

Vasoconstrict alpha 1

44
Q

What does adrenaline do in skeletal muscle and coronary circulation(and with what receptor)?

A

Vasodilation beta 2

45
Q

What does noradrenaline do in skeletal muscle and coronary circulation (and with what receptor)?

A

Vasoconstrictor alpha 1

46
Q

What are the effects of IV adrenaline on circulation?

A

Cardiac output goes up
TPR goes down
Not much effect on blood pressure

47
Q

What is the effect of IV noradrenaline on circulation?

A

Increase in blood pressure
Decrease in heart rate
Increase in TPR
Cardiac output decrease

48
Q

What does RAAS stand for?

A

Renin-angiotensin-aldosterone system

49
Q

Give the steps of RAAS

A

Stimulus causes kidneys to release renin, which combines with angiotensinogen in the liver to produce angiotensin I

Angiotensin converting enzyme then converts that to angiotensin II

50
Q

What does NTS stand for?

A

Nucleus tractus solitarius

51
Q

How is vasopressin released?

A

Stretch receptors in the left atrium send continuous signals to the NTS. NTS sends out inhibitory signals to the CVLM, which stimulates the pituitary gland to release vasopressin

52
Q

What is the hypothalamus response to vasopressin stimulated by?

A

An increase in osmolarity

53
Q

Where is vasopressin released from and what does this cause?

A

Posterior of the pituitary gland which causes increased reabsorption of fluid by kidney and causes vasoconstriction. Both effects maintain blood pressure

54
Q

Where is the NTS?

A

In the medulla

55
Q

What does ANP stand for?

A

Atrial natriuretic peptide

56
Q

What is AMP released by?

A

Specialised atrial myocytes

57
Q

What do stretch receptors act as?

A

ANP receptors on vascular smooth muscle cells increasing the cGMP pathway

Physiology 1 (65 decks)

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