Introduction to the ANS Flashcards
1
Q
Principal target organs of the sympathetic nervous system
A
- pupil dilation
- thick, viscous secretion from salivary glands
- piloerection
- glycogenolysis and gluconeogenesis in liver
- lipolysis in adipose tissue
- detrusor muscle relaxation, constriction of trigone and sphincter (ureters and bladder)
- vasoconstriction for skin, mucous membranes and splanchnic area
- vasodilation for skeletal muscle
- increase heart rate and contractility
- increased renin secretion from kidneys
- increased gastrointestinal motility and tone, sphincter contraction
- bronchodilation
2
Q
Principal target organs of the parasympathetic nervous system
A
- pupil constriction
- ciliary muscle contraction
- copious, watery secretion from salivary glands
- decreased heart rate and contractility
- increased gastrointestinal motility and tone, increased secretions
- detrusor muscle contraction, relaxation of trigone and sphincter (ureters and bladder)
- bronchoconstriction
3
Q
Autonomic nervous system
A
- exocrine glands
- smooth muscle
- cardiac muscle
- metabolism
- host defence
- split into sympathetic and parasympathetic nervous system
4
Q
Somatic nervous system
A
-skeletal muscle (including the diaphragm and respiratory muscle)
5
Q
Neuroendocrine system
A
- growth
- metabolism
- reproduction
- development
- salt and water balance
- host defence
6
Q
Sympathetic nervous system (autonomic)
A
‘fight and flight’
7
Q
Parasympathetic nervous system (autonomic)
A
‘rest and digest’
-linked to secretions
8
Q
Enteric nervous system
A
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9
Q
Nicotinic receptors
A
- found in all autonomic ganglia
- type 1 receptor (ion channel-linked)
- stimulated by nicotine/acetylcholine
- transfer stimulus from pre-ganglionic to post-ganglionic
- VERY FAST
10
Q
Muscarinic receptors
A
- found at all effector organs innervated by post-ganglionic parasympathetic fibres
- stimulated by muscarine/acetylcholine
- type 2 receptor (G-protein coupled)
- SLOWER
11
Q
Sub-types of muscarinic cholinoceptors
A
- M1: neural
- M2: cardiac
- M3: exocrine and smooth muscle
- M4: periphery=prejunctional nerve endings
- M5: striatal dopamine release
12
Q
Adrenoceptors
A
- stimulated by noradrenaline/adrenaline
- type 2 receptors (G-protein-coupled)
- four adrenoceptor subtypes (alpha 1, alpha 2, beta 1 and beta 2)
13
Q
Biosynthesis of acetylcholine
A
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14
Q
Release of acetylcholine
A
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15
Q
Metabolism of acetylcholine
A
Acetylcholinesterase breaks down acetylcholine in synapse to give choline and acetate which reenters presynaptic neurone
-contact with enzyme leads to rapid breakdown
