F3 The autonomic nervous system Flashcards
(77 cards)
1
Q
name the 2 components of the CNS
A
brain
spinal cord
2
Q
describe simply what the PNS is and its function
A
- peripheral nervous system
- neuronal pathways that connect your peripheral organs to the central nervous system
3
Q
what are the 3 broad divisions of the PNS?
A
- sensory nerves
- motor nerves
- autonomic nerves
4
Q
describe the division of the PNS: sensory nerves
A
- involves touch, pain and heat
- travel TO the spinal cord from the periphery eg. skin
- AFFERENT fibres
5
Q
describe the division of the PNS: motor nerves
A
- involve voluntary control of skeletal muscle
- travel AWAY from the spinal cord to the muscle
- SOMATIC EFFERENT system
6
Q
describe the function of the division of the PNS: autonomic nerves
A
unconscious physiological control of organ systems
7
Q
what kind of drugs can the CNS be targeted by and what for?
A
- drugs for CNS disorders
- pain relief
8
Q
what kind of drugs can the sensory nerves of the PNS be targeted by and what for?
A
- pain relief
- local anaesthetics (eg. at the dentist to have a tooth removed)
9
Q
how can the sensory nerves of the PNS be targeted by local anaesthetic when having a tooth removed?
A
local anaesthetic numbs and blocks the sensory nerves from taking any pain signals to the spinal cord
10
Q
what conditions can the motor neurons of the PNS be targeted for?
A
- muscle weakness (myasthenia gravis - autoimmune disorder)
- muscle paralysis during operations
11
Q
what are the 2 divisions of the autonomic nervous system (ANS)
A
- sympathetic (fight or flight)
- parasympathetic (rest and digest)
12
Q
what are the simple functions of the sympathetic and parasympathetic nervous systems?
A
- sympathetic: prepares for activity
- parasympathetic: stimulates visceral processes (those relating to the main internal organs, especially in the abdomen)
13
Q
what is the enteric nervous system? what is its function?
A
- local neuronal network coordinating the GI tract with input from PNS and SNS
- controls the movement and processing of food in the GI tract, controls peristalsis
14
Q
how many neurons do both sympathetic and parasympathetic pathways use?
A
2
15
Q
describe the first neuron involved in sympathetic and parasympathetic pathways
A
- preganglionic neuron
- makes connection (a synapse) with the second neuron in a group of nerve cell bodies known as ganglion
16
Q
describe the second neuron involved in sympathetic and parasympathetic pathways
A
- postganglionic neuron
- innervates (supplies nerves to) the target tissue
17
Q
describe the aspect of the SNS that releases adrenaline into circulation
A
- subset of preganglionic SNS fibres synapse with the adrenal medulla
- this releases adrenaline into the circulation
18
Q
what is the adrenal gland and where is it located?
A
- an endocrine gland that produces adrenaline
- located above the kidneys
19
Q
how many neurons are involved in the motor system and what do they innervate?
A
- 1
- innervates voluntary skeletal muscle
20
Q
from top to bottom (head to bum), state the 6 sections of the vertebrae
A
medullary
cervical
thoracic
lumber
sacral
coccyx
21
Q
describe the preganglionic neurons in the SNS
A
- short
- cell bodies are in the thoracic and lumber sections of the spinal cord
- ganglia are located close to the spinal cord due to short preganglionic neurons
22
Q
where do preganglionic neurons form synapses in the SNS?
A
- paired paravertebral ganglia (bilateral connections to periphery - eg. blood vessels)
- unpaired prevertebral ganglia (intestines, pelvic viscera)
- adrenal medulla
23
Q
in the SNS which ganglionic neurons are long and short?
A
- preganglionic are short
- postganglionic are long
24
Q
in the parasympathetic NS, which ganglionic neurons are short and long?
A
- preganglionic are long
- postganglionic are short
25
where are parasympathetic ganglia located and why?
- located in or close to the target organs due to long preganglionic neurons
26
are parasympathetic or sympathetic ganglia located closer to the spinal cord?
- sympathetic are closer due to having short preganglionic neurons
27
which nerves provide parasympathetic innervation to the heart, lungs and upper GI tract?
- right and left vagus nerves
- (10th cranial nerve, X)
28
state desired physiological effects for exercise
- increased HR
- increased force of heart contractility
- direct blood to skeletal muscles
- increased oxygen intake (open up lung airways)
- increase glucose availability for muscles
- don't go to the toilet
- deprioritise rest and digest functions
29
why are increased HR and force of contractility important during exercise?
- get as much blood into the systemic circulation as possible
30
why is it important for blood to be directed to skeletal muscle during exercise?
- muscles need lots of blood for oxygen for aerobic respiration
- carbon dioxide and lactic acid need to be taken away
31
why is it important for increased oxygen uptake to occur during exercise?
more oxygen into the blood and more carbon dioxide out of the body
32
why is it important for increased glucose to be available during exercise?
more glucose needs to be produced by breaking down glycogen so it can be used in aerobic respiration
33
what is the effect of the sympathetic nervous system on the heart?
- increased rate
- increased force of contractility
34
what is the effect of the sympathetic nervous system on the arterioles of the GIT, skin and brain?
constriction
35
what is the effect of the sympathetic nervous system on the arterioles at skeletal muscles?
relaxation
36
what is vascular shunt?
- directing blood to working muscles
- diverts blood away from muscles that don't need lots of blood at this time
37
what part of the NS controls vascular shunt?
sympathetic
38
what is the effect of the sympathetic nervous system on the lungs?
bronchodilation
39
what is the effect of the sympathetic nervous system on the GIT?
- decreased motility
- sphincter constriction
- no effect on secretion
40
what is the effect of the sympathetic nervous system on the bladder?
- relaxation
- sphincter constriction
41
what is the effect of the sympathetic nervous system on the liver?
- increased glucose production from glycogen and other substrates
42
what is the effect of the sympathetic nervous system on the skin?
- piloerection
- sweat gland secretion
43
what is the effect of the sympathetic nervous system on the salivary glands?
secretion
44
what is the effect of the parasympathetic nervous system on the heart?
- decreased rate
- decreased force
45
what is the effect of the parasympathetic nervous system on the arterioles?
no effect
46
what is the effect of the parasympathetic nervous system on the lungs?
bronchoconstriction
47
what is the effect of the parasympathetic nervous system on the GIT?
- increased motility
- increased secretion
- sphincter relaxation
48
what is the effect of the parasympathetic nervous system on the bladder?
- contraction
- sphincter relaxation
49
what is the effect of the parasympathetic nervous system on the liver?
no effect
50
what is the effect of the parasympathetic nervous system on the skin?
no effect
51
what is the effect of the parasympathetic nervous system on the salivary glands?
secretion
52
what things do the SNS and PNS have opposing actions on?
- heart rate
- airway tone
- GI motility
53
what things do the SNS and PNS have single system control on? give example for each
- sympathetic: liver
- parasympathetic: GI secretion
54
what things do the SNS and PNS have coordinated actions on? be specific
- salivary secretion of:
- fluid (parasympathetic)
- enzymes (sympathetic)
55
which 2 of noradrenaline, adrenaline and acetylcholine are neurotransmitters? what is the other?
- acetylcholine and noradrenaline are neurotransmitters
- adrenaline is a hormone
56
describe nicotinic receptors
- ligand-gated ion channels
- 'fast' ion channels
- they produce their signal very fast and the signal is carried along the postganglionic neuron to the target organ
57
describe muscarinic receptors
- G protein coupled receptors
- 'flexible'
58
which molecules will activate nicotinic and muscarinic receptors?
- nicotine and muscarine
59
what are adrenoceptors?
- G protein coupled receptors
- connected to different signalling pathways
60
what are the 5 subtypes of adrenoceptors?
alpha 1
alpha 2
beta 1
beta 2
beta 3
61
what is the neurotransmitter for all preganglionic neurons?
acetylcholine
62
what does ACh allow for in both the SNS and PNS?
- fast ganglionic transmission
- stimulates ligand-gated ion channels at synapses
63
how is ACh used in the parasympathetic NS?
- main parasympathetic NT
- activates muscarinic receptors on targets
64
what are the main sympathetic mediators?
- noradrenaline / adrenaline
- activate adrenoceptors
65
what is an exception in the SNS for what mediator is used for activation?
sympathetic innervation of the sweat glands uses acetylcholine and muscarinic receptors
66
what receptor is involved in the sympathetic NS effect on the heart?
beta 1 adrenoceptor
67
what receptor is involved in the sympathetic NS effect on the arterioles of the GIT, skin and brain?
alpha 1 adrenoceptor
68
what receptor is involved in the sympathetic NS effect on the arterioles of skeletal muscle?
beta 2 adrenoceptor
69
what receptor is involved in the sympathetic NS effect on the lungs?
beta 2 adrenoceptor
70
which 3 receptors are involved in the sympathetic NS effect on the GI tract?
alpha 1, alpha 2 and beta 2 adrenoceptors
71
what receptor is involved in the sympathetic NS effect of relaxation on the bladder?
beta 2 adrenoceptor
72
what receptor is involved in the sympathetic NS effect of sphincter constriction on the bladder?
alpha 1 adrenoceptor
73
what receptors are involved in the sympathetic NS effect on the liver?
alpha 1 and beta 2 adrenoceptors
74
what receptor is involved in the sympathetic NS effect of piloerection on the skin?
alpha 1 adrenoceptor
75
what molecule at what receptor is involved in the sympathetic NS effect of sweat gland secretion on the skin?
acetylcholine at muscarinic receptor
76
what receptors are involved in the sympathetic NS effect on the salivary glands?
alpha and beta adrenoceptors
77
explain how salbutamol is selective
- selective for beta 2 adrenoceptors in the lungs over the beta 1 adrenoceptors in the heart
- higher affinity to beta 2 receptors
- opens airways and treats bronchoconstriction without affecting the heart too much
