Week 14: Intro to Autonomic Nervous System Flashcards
What are the 2 parts to the nervous system?
Peripheral and central
What are the 2 parts of the central nervous system?
brain and spinal cord
What type of signal goes from the CNS to PNS?
efferent
What type of signal goes from the PNS to CNS?
afferent
What are the 3 sub-divisions of the PNS?
Somatic afferent (to skeletal muscle), autonomic & somatic efferent (from skeletal muscle)
What are the 3 sub-divisions of the autonomic nervous system?
enteric, sympathetic & parasympathetic
What do the somatic efferent supply?
skeletal, voluntary & striated
Where do somatic afferent send info to?
send info to the CNS from skin, joints, skeletal muscle
What components does the autonomic nervous system have?
motor and sensory components
Where are the cell bodies and fibres of the enteric nervous system found?
entirely within the wall of the gut
What does the autonomic nervous system mediate?
output from the CNS to the whole body
What muscle type does the ANS not mediate output?
the skeletal (voluntary) muscle
What is output modulated by?
external and internal sensory output
often via reflexes involving negative feedback loops within PNS & CNS
What is an example of a negative feedback loop of the ANS?
fall in bp pressure sensed by afferent fibres, send a drop in bp to the brains stem
autonomic output to the heart among other organs is modified
increase bp
What is an example of training the ANS?
learn when to pee & poo!
What are the 2 neurones called in the ANS?
preganglionic and postganglionic neurone
Where is the head of the preganglionic neurone located in the ANS?
inside CNS
What is the autonomic. ganglion?
located outside the CNS
What does the postganglionic neurone signal to?
effector cells
What is the ganglion?
collection of nerve cells present in periphery.
like a nucleus in the brain
In the ANS, does parasympathetic or sympathetic pathway have a longer preganglionic neurone?
parasympathetic
What neurotransmitter is always released from the preganglionic neurone? (ANS)
ACh
What does receptor does ACh activate in the head of the postganglionic neurone?
nicotinic nicotinic cholinoreceptors
nAChR
What receptor does ACh effect. on the effector cells?
parasympathetic
muscarinic cholinoreceptors
What neurotransmitter is released from sympathetic postganglionic. neurones?
noradrenaline
What receptor does noradrenaline act upon on effector cells?
adrenoreceptor
What is a neurone called that synthesises and releases ACh?
cholinergic
What is a neurone called that synthesises and releases noradrenaline?
adrenergic
What type of receptor is a post ganglionic receptor that ACh binds?
G-protein coupled muscarinic acetylcholine receptor
parasympathetic
What is transmission called when ACh and NA are not solely released from the post-ganglionic fibres?
non-adrenergic, non-cholinergic (NANC)
what is ACh and NA co-released with or instead of?
NANC
What is co-released with NA? From sympathetic fibres
ATP, Neuropeptide Y(NPY)
What is co-released with ACh? From parasympathetic fibres
nitric oxide, vasoactive intestinal peptide (VIP)
What are the rapid response neurotransmitters in para and sympathetic fibres?
para= ACh symp= ATP
What are the intermediate response transmitters in para and sympathetic fibres?
Para= nitric oxide Symp= noradrenaline
What are the slow response transmitters in para and sympathetic fibres?
para= VIP Symp= NYP
Give an example of chemical co-transmission in tension of vascular smooth muscle in the sympathetic ANS?
- ATP produces a fast contraction of smooth muscle.
- NorA produces a moderately fast response
- NPY produces slow response
Give an example of chemical co-transmission in tension of vascular smooth muscle in the parasympathetic ANS?
- ACh and norA produce a rapid relaxation
2. VIP produces slow delayed response
Do most blood vessels contain parasympathetic blood supply?
NO, penis does
What is the slowest of the neurotransmitters?
the peptides
VIP, NPY
What type of agonist is ACh?
endogenous of cholineR, nicotinic or muscarinic
What type of receptor is the nicotinic AChR of the ganglia?
ligand gated ion channel
(LGICs) selectively activated by ACh and nicotine
What is the difference ganglia receptors and effector cell receptors of the parasympathetic system?
ganglia R: Ligand-gated ion channels
Effector cell: Muscarinic AChR
What activates the muscarinic AChR?
muscarine & ACh
How many sub-types does muscarinic AChR have? (post ganglionic parasympathetic)
M1-5
M1-3 most important in the ANS
what agonists are endogenous to a family of adrenoreceptors?
And what is the family?
Na and adrenaline,
all g-protein-coupled receptors
What are the sub-types of the adrenoreceptors?
alpha and beta
Order of binding agonists on the alpha-adrenoR?
NA> Adrenaline> isoprenaline
Order of binding agonists on the beta-adrenoR?
isoprenaline> adrenaline> noradrenaline
What are the sub-classes of alpha & beta adrenoreceptors?
alpha 1,2
beta 1,2,3
