Autonomic NMJ pharmacology

Question 1

What transmitter and receptor type are used in the somatic nervous system?

Answer 1

Acetyl Choline

Nicotinic

Question 2

What transmitter and receptor type is used in the sympathetic autonomic nervous system?

Answer 2

Ganglionic: ACh + nicotinic

Post-ganglionic: NA or A/NA + adrenergic (alpha or beta)

Question 3

What transmitter and receptor type is used in parasympathetic autonomic nervous system?

Answer 3

Ganglionic: ACh + nicotinic

Post-ganglionic: ACh + muscarinic

Question 4

At the somatic NMJ:

What effect would hemicholnium have?

(Inhibits choline transporters)

Answer 4

Inhibit choline transporter (in all cholinergic receptors)

Stops ACh being packed into vesicles

Stops ACh release - paralysis

Question 5

What is a non-depolarising nicotinic receptor blocker, such as D-tubocurarine?

Answer 5

A bloody mouthful

Antagonist to the receptor - will bind but has no efficacy

Question 6

Depolarising nicotinic receptor blockers have the same overall effect of paralysis, as the other blockers etc…

How does this work?

Answer 6

Activates ion channel and keeps it open

Brief period of twitching, followed by paralysis

Voltage gated ion channels remain in refractory state

Question 7

For what reasons are non-depolarising or polarising blockers used clinically?

Answer 7

Surgery
Electroconvulsive therapy
Tetanus

Question 8

Botulinum toxin poisoning can be countered using what?

Answer 8

Anticholinesterases

Question 9

Aside from countering Botulinum toxin poisoning, what are the clinical uses of anticholinesterses?

Answer 9

Treating myasthenic syndromes

Reversing action of non-depolarising blockers

Question 10

What are the clinical applications of blockers etc that target ganglionic transmission of the ANS?

Answer 10

There aren’t any

Blocking anything would cause too many side effects

Question 11

What are the effects of muscarinic agonists and antagonists on the body?

Answer 11

Agonists mimic effect of parasympathetic stimulation - rest + digest

Antagonists block effect of the parasympathetic system - fight or flight

Question 12

If you gave a patient a dosage of carbachol (muscarnic agonist) , what would happen?

Answer 12

Stimulates parasympathetic - reduced heart rate, increased enzyme secretion, increased gut motility, pupils constrict

Question 13

Alpha and beta agonists/antagonists would do stuff where?

Answer 13

At the site of sympathetic post-ganglionic transmission

Question 14

Why are beta2 agonists used clinically?

Answer 14

Salbutamol - asthma

Relaxes airways (sympathetic stimulation)

Question 15

What type of agonist/antagonist is used to treat hypertension?

Answer 15

alpha 2 agonists

Question 16

Where would you find nicotinic receptors?

Answer 16

NMJ (somatic nervous system)

Ganglia of ANS

Question 17

Adrenergic receptors

Ionotropic or metabotropic?

Answer 17

Metabotropic

Question 18

An agonist binds to an alpha 1 receptor

What is the effect?

Answer 18

Smooth muscle contraction

Question 19

An agonist binds to an alpha 2 receptor

What is the effect?

Answer 19

Smooth muscle contraction

Question 20

What effect does a beta 1 receptor have, when bound to by an agonist?

Answer 20

Cardiac muscle contraction

Question 21

When a beta 2 receptor is bound to by an agonist, what is the effect?

Answer 21

Smooth muscle relaxation

Question 22

What is propranolol?

Answer 22

Beta 1 blocker used in the treatment of hypertension

Question 23

What is doxazosin?

Answer 23

Alpha 1 receptor antagonist used in hypertension treatment