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Flashcards in Session 10 Deck (30)
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1

What neurotransmitter do pre-ganglionic neurones use in the Sympathetic branch of the ANS?

Acetylcholine

2

What neurotransmitter do pre-ganglionic neurones use in the Parasynpathetic branch of the ANS?

Acetylcholine

3

What neurotransmitter do post-ganglionic neurones use in the Sympathetic branch of the ANS?

Noradrenaline

4

What neurotransmitter do post-ganglionic neurones use in the Parasympathetic branch of the ANS?

Acetylcholine

5

What receptors receive acetylcholine in the ANS?

Nicotinic

6

What is Acetylcholine synthesised from?

Choline using the choline acetyltransferase enzyme

7

What are NANC transmitters?

Non Adrenergic, Non Cholinergic transmitters.

8

When are NANC transmitters released?

They can be co released with Noradrenaline/Acetylcholine

9

What are some examples of NANC transmitters?

NO
ATP
5HT

10

What are the 2 termination mechanisms of noradrenaline?

Uptake 1
Uptake 2

11

What is Uptake 1?

Noradrenaline is terminated by reuptake into the presynaptic terminal by a Na+ dependent transporter

12

What is Uptake 2?

Noradrenaline is not recaptured by Uptake 1 and is taken up by a lower affinity non neuronal mechanism

13

What degrades Acetylcholine?

Cholinesterase in the synaptic cleft

14

If Acetylcholine is not broken down by Cholinesterase, where can it go?

Into synaptic vesicles

15

What breaks down cytoplasmic noradrenaline?

Monoamine Oxide

16

What is Noradrenaline synthesised from?

Tyrosine in the nerve terminal

17

What are the 4 main classes of drugs which act on the ANS?

Nicotinic Cholinoceptor Antagonists
Muscarinic Cholinoceptor Agonists
Muscarinic Cholinoceptor Antagonist
Cholinesterase Inhibitors

18

What type of drug is Pilocarpine?

Muscarinic Cholinoceptor Agonist

19

What is Pilocarpine used for clinically?

Treatment of Glucomas

20

What type of dug is Tubocurarine?

Nicotinic Cholinoceptor Antagonist used for muscle paralysis

21

What type of drug can be used to treat Myasthenia Gravis?

Cholinesterase Inhibitors

22

What Muscarinic Cholinoceptor Antagonist can be used for pupil dilation?

Tropicamide

23

What is alpha Methyl-tyrosine?

A drug that completely blocks tyrosine hydroxylase so synthesis of noradrenaline is stopped

24

When is alpha Methyl-tyrosine used clinically?

In Pheochromocytoma

25

What is alpha-Methyl-DOPA?

It inhibits voltage operated calcium channels

26

How does alpha Methyl DOPA inhibit VOCC?

Acts like noradrenaline, but poorly metabolised so accumulates in synaptic vesicles.
When these are released it acts on pre synaptic alpha 2 receptors which inhibit VOCC and reduce Ca2+mediated release

27

What is CarbiDOPA?

Inhibits DOPA decarbocylase, but ONLY in the peripheral nervous system as it cannot cross the BBB

28

How do Adrenergic Blocking Drugs work?

Reducing impulse conduction
Reduces Ca2+ mediated exocytosis
Reduces repletion of Noradrenaline

29

How do Indirectly-acting Sympathomimetic Agents (IASAs) work?

They are taken into vesicles by Uptake 1.
The displaced Noradrenaline will leak into the synaptic cleft.
This can inhibit Noradrenaline degrading enzyme - MAO

30

Give an example of Uptake 1 Inhibitors?

Tricyclic antidepressants. Exert action centrally, possible peripheral actions are side effects