Autonomic Pharmacology: Basics

Question 1

What is CNS?

Answer 1

The brain and spinal cord

Question 2

What is PNS?

Answer 2

Everything that’s not the CNS

Question 3

What is autonomic nervous system?

Answer 3

Sympathetic, parasympathetic, enteric

Question 4

Preganglionic fibres are a part of which nervous system?

Answer 4

CNS

Question 5

Where could postganglionic fibres be?

Answer 5

In the sympathetic chain, ganglia, or the surface of organs

Question 6

What are postganglionic fibres and cell bodies a part of?

Answer 6

The PNS

Question 7

What is ANS a part of?

Answer 7

PNS

Question 8

What exactly does the ANS control?

Answer 8

Involuntary motor functions

Question 9

What are some examples of functions controlled by ANS?

Answer 9

-heartbeat
-contraction of vascular and visceral smooth muscles
-all exocrine and some endocrine secretions
-aspects of metabolism

Question 10

What kind of Preganglionic fibres does sympathetic and parasympathetic have?

Answer 10

Cholinergic Preganglionic fibres that release Acetylcholine

Question 11

Where does the ACh from ANS Preganglionic fibres bind to?

Answer 11

The nicotinic choliceptors on postganglionic cell bodies

Question 12

What kind of postganglionic fibres does ANS have?

Answer 12

Sympathetic has Adrenergic postganglionic fibres that release noradrenaline
Parasympathetic has cholinergic postganglionic fibres that release ACh

Question 13

Where does the ACh and noradrenaline of postganglionic fibres bind to?

Answer 13

For noradrenaline, binds to adrenoceptors at the effector
For ACh, binds to muscarinic cholinoceptors at the effector

Question 14

Where does the sympathetic nerves leave the CNS?

Answer 14

T1-L2/3 (thoracolumbar outflow)

Question 15

How do sympathetic nerve impulses travel?

Answer 15

Sympathetic nerve impulses begin in the CNS and go down the spinal cord. Preganglionic nerve fibres exit the spinal cord via ventral roots of T1-L2/3 and release ACh which acts on nAChR on postganglionic cell bodies located at the sympathetic chain. The postganglionic fibres then release noradrenaline which acts on adrenoceptors at effectors

Question 16

What type of receptor are adrenoceptors ?

Answer 16

GPCR

Question 17

What are other neurotransmitters released by sympathetic that’s not noradrenaline?

Answer 17

ATP (rapid response) and neuropeptide Y (slow response)

Question 18

What are some examples of functions parasympathetic nervous system controls?

Answer 18

-decreases heart rate
-broncoconstriction
-increased gut motility
-decrease gut sphincter motility
-relaxes bladder sphincter

Question 19

Where do the parasympathetic nerve impulses leave the CNS?

Answer 19

Cranial nerves (CN III, VII, IX, X) and spinal nerves S2,3,4 (craniosacral outflow)

Question 20

How do parasympathetic nerve impulses travel?

Answer 20

Parasympathetic nerve impulses leave the CNS either through cranial nerves CN III, VII, IX, X or spinal nerves S2,3,4 (craniosacral outflow). The Preganglionic nerve fibre releases acetylcholine which acts on nAChR on postganglionic cell bodies. The postganglionic nerve fibres have short axons and release acetylcholine which acts on mAChR on effectors

Question 21

What kind of receptor is muscarinic acetylcholine receptors?

Answer 21

GPCR

Question 22

What are some NANC neurotransmitters of parasympathetic?

Answer 22

NO (intermediate response) and vasoactive peptide P (slow response)

Question 23

What kind of receptors are nicotinic acetylcholine receptors?

Answer 23

Ligand-gated ion channels

Question 24

What are some functions of the diff types of mAChR?

Answer 24

M1 - increased acid secretion in stomach
M2 - decreased heart rate
M3 - increased salivation

Question 25

What are the steps of transmission?

Answer 25

-A precursor of neurotransmitter is taken into the cell
-the precursor is metabolised into a neurotransmitter
-the neurotransmitter is stored
-depolarisation from an action potential causes an influx of Ca2+
-influx of Ca2+ induces release of neurotransmitter
-neurotransmitter activates its receptors on post-synaptic cell
-neurotransmitter either becomes inactivated (cholinergic) or reuptaken (adrenergic)