L9: Drugs affecting the PNS

Question 1

What is the autonomic NS involved in?

Answer 1

Constant involuntary control of essential organs & functions

Question 2

Subdivisions of the autonomic NS

Answer 2

1) Sympathetic NS
2) Parasympathetic NS

Question 3

Function of sympathetic NS

Answer 3

Flight or fright

Question 4

Function of parasympathetic NS

Answer 4

Activated at rest

Question 5

Define ganglion

Answer 5

“Swelling” which contains a chemical synapse

Question 6

Function of efferent nerves of parasympathetic NS

Answer 6

Leave the spinal cord in the medullary & sacral regions and carried by a system of pre-ganglionic & post-ganglionic nerve

Question 7

Where does chemical synaptic transmission occur?

Answer 7

Ganglia & the “neuro-effector junction”

Question 8

Define “neuro-effector junction”

Answer 8

Synpase between post ganglionic nerve & organ being controlled

Question 9

Key neurotransmitter in the parasympathetic NS

Answer 9

Acetylcholine (ACh)

Question 10

How does ACh play a role as neurotransmitter in the ganglia & neuroeffector junctions?

Answer 10

Released from both pre- & post-ganglionic nerves

Question 11

What does ACh act on in the ganglia?

Answer 11

On nictotinic receptors found on post-ganglionic nerves

Question 12

What does ACh act on in the neuroeffector junction?

Answer 12

On muscarinic receptors found on cells of target organ

Question 13

Function of efferent nerves of the sympathetic NS

Answer 13

Leaves the spinal cord in the thoracic & lumbar regions

Question 14

Compare pre-ganglionic nerve fibres between SNS & PSNS

Answer 14

SNS pre-ganglionic nerve fibres are shorter than post-ganglionic nerve, but PSNS is the opposite way around

Question 15

Key neurotransmitters in the sympathetic NS

Answer 15

ACh & noradrenaline

Question 16

2 receptors found in PSNS

Answer 16

1) Nicotinic (ganglia)
2) Muscarinic (NEJ)

Question 17

Receptors in the SNS

Answer 17

1) Nicotinic (ganglia)
2) Muscarinic (sweat glands)

Question 18

2 types of ACh receptors

Answer 18

1) Nicotinic
2) Musarinic

Question 19

Where is “ganglionic” nicotinic ACh receptors found?

Answer 19

In the ganglia of both PSNS & SNS

Question 20

Where is muscarinic ACh receptors found?

Answer 20

At the neuroeffector junctions of the parasympathetic NS

Question 21

Action of inhibitors of acetylcholinesterase

Answer 21

Enhance the effects of ACh by preventing its destruction

Question 22

3 types of inhibitors of acetylcholinesterase

Answer 22

1) Edrophonium
2) Neostigmine
3) Irreversible, organophosphates