Pharm 1 - Intro to ANS Flashcards
What are the 3 outputs of the CNS?
- ANS
- Somatic NS
- Neuroendocrine system
Name 3 PNS dominant actions
- Pupil constriction
- Lungs
- Cephalic & gastric phases
Which liver actions are SNS mediated?
Glycogenolysis, gluconeogenesis
What nerves are baroreceptors stimulatory to?
PNS
What nerves are baroreceptors inhibitory to?
SNS
PNS is discrete and localised. What is the ratio of pre vs post ganglion?
1:1
SNS is coordinated and divergent. What is the ratio of pre vs post ganglion?
1:20
What receptor is present on all autonomic ganglia?
Nicotinic receptor
Are nicotinic receptors rapid or slow?
Rapid
What type of receptor is the nicotinic receptor?
Type 1 ionotropic receptor
How does the nicotinic receptor work?
- ACh / nicotine binds to receptor. This causes a Na+/Ca2+ influx.
- This allows transmission of signal
Where are muscarinic receptors always present?
Post ganglionic PNS nerve fibres.
What is the unusual exception to muscarinic receptors?
Present on post-ganglionic SNS fibre when innervating sweat glands
What type of receptor is the muscarinic receptor?
Type 2 - G protein coupled receptor
Are muscarinic receptors faster or slower?
Slower
What 2 substances can stimulate muscarinic receptors?
ACh / muscarine
What does blocking the NAChR at rest do to HR?
Increase HR
What does blocking the NAChR during exercise do to HR?
Decrease HR
Blocking NAChR at rest does what?
- Decreases gut motility - constipation
- Bronchodilation
- Long-sightedness
- Decreased urinary frequency
How many types of muscarinic receptors are there?
5
M1 receptors are?
Neural - located in the forebrain - important in learning and memory
M2 receptors are?
Cardiac - located in the brain, inhibitory auto receptors
M3 receptors are?
Exocrine and SM - hypothalamus - food intake
M4 and M5 are?
Peripheral (pre junctional nerve endings) and stratal dopamine release respectively
What type of receptor are adrenoreceptors?
G protein coupled (Type 2)
alpha 1 and alpha 2 adrenoreceptors do what?
Constrict
Beta 1 and beta 2 adrenoreceptors do what?
Dilate
What 2 effects will blocking muscarinic receptors have during exercise?
- Increase HR
2. Decrease sweat production
Explain how NA is synthesised
- Tyrosine –> DOPA (via tyrosine hydroxyls)
- DOPA -> Dopamine (DOPA decarboxylase)
- Dopamine -> NA (Dopamine Beta-hydroxylase)
Once NA has had its effects, it has two ways of being removed. What are they?
- Metabolised by MAO-A (preganglionic) - UPTAKE 1
2. Degraded by COMT (post ganglionic) - UPTAKE 2
