Autonomic Nervous System Flashcards
What does the activation of B1 adrenoreceptors lead to?
An increase in cAMP
What are beta adrenal receptors more sensitive to?
Adrenaline
What are alpha 1 adrenal receptors coupled to?
Phospholipase C
= increase in calcium
What are the B-adrenoreceptors coupled to?
Adenylate cyclise
Increase in phospolipase C
what neurotransmitter is released in every ganglia? (pre-ganglionic)
acetylcholine
what is the length of the pre-ganglionic fibre in the PNS?
long pre-ganglionic fibre
what is the length of the pre-ganglionic fibre in the SNS?
short pre-ganglionic fibre
what are examples of single input tissues, in the SNS?
blood vessels
sweat glands
what are example of single input tissues in the PNS?
bronchial smooth muscle
ciliary muscle of the eye
How are nicotinic acetylcholine receptors activated?
by the binding of 2 molecules of acetylcholine which causes an ion pathway to open
what does the activation of M3 receptors cause?
causes the contraction of non-vascular smooth muscle.
what is the cause of M3 receptor activation?
M3 receptors are coupled to phospholipase C.
There is increased activation of phospholipase C
= increased calcium release
what receptor type are secretions controlled by?
Muscarinic receptors
what receptors do acetylcholine bind to?
nicotinic receptors
where are parasympathetic nerves found?
salivary glands
GI tract
Heart
where are sympathetic nerves found?
arteries
sweat glands
adrenal glands
heart
what is the outflow of the sympathetic system?
thoraco-lumbar
what is the outflow of the parasympathetic system?
cranio-saccral
what is the cranial nerve X also referred to?
Vagus
this goes to the heart, kidneys, GI tract and colon
what does the vagal nerve do to the cardiovascular system?
it slows the heart rate
what are some of the physiological responses that the PNS produces?
pupil constriction
slows heart rate
stimulates urination
stimulates saliva and tear production
what are some of the physiological responses that the SNS produces?
vascular smooth muscle contraction
increases cardiac rate and force
airway relaxation and vascular dilatation
what post-ganglionic chemical is released from the PNS?
acetylcholine
what post-ganglionic chemical is released from the SNS?
noradrenaline
In the SNS, what are the types of receptors?
Adrenoreceptors
Alpha 1,2
Beta 1,2,3
In the PNS, what are the types of receptors?
Muscarininc receptors
M1-5
what do adrenoreceptors release?
noradrenaline
what do muscarinic receptors release
acetylcholine
what does alpha 1 receptor cause? (sympathetic effect)
contraction of vascular smooth muscle
what does alpha 2 receptor cause? (sympathetic effect)
inhibition of transmitter release
what does Beta 1 receptors cause? (sympathetic effect)
main cardiac effects
what does beta 2 receptors cause? (sympathetic effect)
relaxation of airways/vascular dilatation
what is the cause of contraction of arterial smooth muscle?
adrenaline/noradrenaline interacts with alpha 1 adrenoreceptors
= increase in phospholipase C
what is the cause of the inhibition of sympathetic nerve transmission?
decreased adenylate cyclase = reduced release and influx of calcium
which muscarinic receptors have phospholipase C as their enzyme?
M1, M3 and M5
the odds
which muscarinic receptors have adenylate cyclase as their enzyme?
M2 and M4
what are the cardiac effects due to M2 muscarinic receptor activation?
decreased cardiac activity due to a decrease in cAMP
which receptor contracts non-vascular smooth muscle?
M3
which receptor contracts vascular smooth muscle
alpha 1
what is the effect of M3 receptors on secretory cells?
increases secretions
Botulinum toxin paralyses muscles. What mechanism underlies this effect?
It degrades vesicle release proteins
Fusion of the vesicle storing acetylcholine with the cell membrane is mediated by vesicular release or SNARE proteins that couple in a calcium-dependent manner. These SNARE proteins are degraded by Botulinum Toxin (BoTox) as well as beta-Bungarotoxin.
