Autonomic NS Flashcards
Where does cranial nerve III lead to?
Eye
Where does cranial nerve VII lead to?
Lacrimal glands and salivary glands
Where does cranial nerve IX lead to?
Salivary glands
Where does cranial nerve X lead to?
Heart
Lungs
Upper GI tract
The preganglionic neurone tend to be myelinated or unmyelinated?
Myelinated
The postganglionic neurone tends to be myelinated or unmyelinated?
Unmyelinated
Where do the parasympathetic neurones usually synapse?
Near the target tissue
Long preganglionic neurone
Where do the sympathetic neurones usually synapse?
In the paravertebral chain
Short preganglionic neurones
What do we call the transmitters in the ANS that aren’t NA or ACh?
Non-adrenergic, non-cholinergic transmitters (NANC transmitters)
What type of muscarinic receptor is present at SAN and AVN?
M2
G alpha i
What type of muscarinic receptor is present in the lungs?
M3
G alpha q
Penile erection requires the production of which transmitter?
Nitric oxide
Which adrenoceptor is present in the SAN and ventricles?
Beta 1
G alpha s
Which adrenoceptor is present in the vasculature?
Alpha 1
G alpha q
Which adrenoceptor is present in the lungs?
Beta 2
G alpha s
What is dysautonomia?
Distinct malfunctions of the ANS
Can be primary or secondary
We can use prenatal diagnosis to detect
What is pheochromocytoma?
Cancerous growth of Chromaffin cells
Produces adrenaline/NA
Body goes into sympathetic overdrive eg. Tachycardia, sweating
What are the most common sites of drug action in the ANS?
Degradation of transmitter Interaction with post-synaptic receptors Inactivation of transmitter Reuptake of transmitter Interaction with pre-synaptic receptors
Describe the formation of acetylcholine
Acetyl CoA and choline
React with choline acetyltransferase
Produces acetylcholine and coenzyme A
Describe the breakdown of ACh
Acetylcholine broken down by acetylcholinesterase
Forms acetate and choline
When is trimethaphan used?
Hypertensive emergencies or to produce hypotension in surgery
(Blocks nAChR at ganglia - has many side effects)
What can acetylcholinesterase inhibitors be used to treat?
Myasthenia gravis
Alzheimer’s
What is Sludge syndrome?
Massive discharge of parasympathetic NS
Can be due to drug overdose or nerve gases
Salivation, lacrimal in, urination, defecation, GI upset and emesis
What can muscarinic agonists be used for?
Treat glaucoma
Stimulate bladder emptying
What can we treat with muscarinic antagonists?
Asthma
COPD
Overactive bladder
Which enzyme converts dopamine to NA?
Dopamine beta hydroxylase
How is NA action terminated?
Uptake 1 - Na+ dependent, high affinity
Uptake 2 - lower affinity
Which enzymes metabolise NA?
MAO = mono amine oxidase
COMT
How can alpha 2 adrenoceptors reduce neurotransmitter release?
NA binds to GCPR (G alpha i) Beta-gamma subunit binds to VOCCs Inhibits VOCCs Reduces calcium influx Reduces neurotransmitter release (exocytosis)
What is carvedilol?
A mixed beta 1/beta 2/alpha 1 adrenoceptor antagonist
Useful for chronic heart failure
