Flashcards in CVS S4 - The CVS & The Autonomic Nervous System Deck (33)
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Describe pre-ganglionic neurones in the parasympathetic nervous system
Have their cell bodies in the CNS
Cholinergic
Nerve fibres are long
1
Describe preganglionic neurones in the sympathetic nervous system
Have their cell bodies in the CNS
Cholinergic
Nerve fibres are short
Arise from segments T1-L2 or L3
3
Describe post-ganglionic neurones in the parasympathetic nervous system
Have their cell bodies in the PNS
Noradrenergic (α and β classes, types 1 and 2)
*EXCEPTION* perspiration and ejaculation pathways cholinergic
Short nerve fibres
4
Describe post-ganglionic neurones in the sympathetic nervous system
Have their cell bodies in the PNS
Cholinergic receptors
Specifically muscarinic receptors and GPCRs
Nerve fibres are long
5
Give examples of effectors of the autonomic nervous system
Smooth muscle
Viscera
Secretory glands
6
Describe the sympathetic nervous system
Thoraco-lumbar outflow
Nerve fibres have cell bodies in all 12 thoracic sections and the first two lumbar sections
Pre-ganglionic neurones have short nerve fibres and are cholinergic
Post-ganglionic neurones have long nerve fibre and are noradrenergic EXCEPT the perspiration ejaculation pathways which are cholinergic
7
Describe the locations of synapses in the parasympathetic nervous system
Usually synapse close to target tissue
8
Describe the location of synapses in the sympathetic nervous system
Most synapse with post-ganglionic neurones at the para vertebral chain of ganglia
Some synapse in a number of prevertebral ganglia: coeliac, superior and inferior mesenteric ganglia
10
Describe the parasympathetic nervous system
Cranio-sacral outflow
Pre-ganglionic neurones have long nerve fibres and are cholinergic (nicotinic)
Post-ganglionic neurones have short nerve fibre and are cholinergic (muscarinic or GPCR)
11
Give the effect and the receptor of sympathetic stimulation to the heart
Sympathetic:
Receptor is β1
Effect is to increase the force of rate of contraction
Parasympathetic:
Receptor is M2
Effect is to decrease the rate of contraction
12
Give the effect and the receptor of parasympathetic stimulation to the heart
Receptor is M2
Effect is to decrease the rate of contraction
13
Give the effect and the receptor of sympathetic stimulation to the airways
Receptor is β2
Effect is to relax the airways
14
Give the effect and the receptor of parasympathetic stimulation to the airways
Receptor is α1
Effect is to contract the airways
15
Give the effect and the receptor of sympathetic stimulation to the pupils
Receptor is α1
Effect is to dilate the pupils
16
Give the effect and the receptor of parasympathetic stimulation to the pupils
Receptor is M3
Effect is to contract the pupils
17
Which type of GPCR stimulates adenylyl cyclase?
The s type: Gs
18
Which type of GPCR inhibits adenylyl cyclase?
The i type: Gi
19
Which type of GPCR stimulates phospholipase C?
The q type: Gq
20
Which type of GPCR stimulates cyclic GMP?
The t type: Gt
21
Which receptors cause the stimulation of adenylyl cyclase?
β1 and β2
22
Which receptors cause the inhibition of adenylyl cyclase?
α2 and M2
23
Which receptors cause the stimulation of phospholipase C?
α1, M1 and M3
24
Describe how the sympathetic nervous system innervates vasculature
Sympathetic NS innervates the smooth muscle of arteries, arterioles and veins
Stimulation causes vasoconstriction via α1 receptors
EXCEPT in specialised vessels eg erectile tissue
25
What is the effect of sympathetic stimulation on vasculature?
Stimulation causes vasoconstriction via α1 receptors
EXCEPT in specialised vessels eg erectile tissue
26
How is vasomotor tone controlled?
By the balance between sympathetic stimulation and vasodilator substances
This in turn controls flow around the cvs
27
How variable is vasomotor tone?
It varies between organs and can be changed quickly
28
Describe how vasomotor tone in the skin changes
Skin usually has very high vasomotor tone but for thermoregulation, tone can be reduced
29
Describe how vasomotor tone in skeletal muscle changes
At rest, skeletal muscle has high vasomotor tone but during exercise, this is antagonised by vasodilator metabolites
30
Describe how vasomotor tone in the gut changes
Before a meal, the gut has high vasomotor tone but after eating, various vasodilators are produced in the gut to antagonise sympathetic stimulation
31
