Neurotransmitter

Question 1

What are neurotransmitters?

Answer 1

Endogenous chemicals that allow neurons to communicate within the ANS and CNS.

Question 2

List the main neurotransmitters in the autonomic nervous system (ANS).

Answer 2

catecholamines (dopamine)

Acetylcholine

Question 3

What are parasympathomimetics?

Answer 3

Agents that stimulate parasympathetic nerves also known as cholinergic agonists or cholinoceptor stimulants.

Question 4

Name examples of cholinergic agonists that act on muscarinic receptors.

Answer 4

carbachol. Methacholine

Question 5

What are parasympatholytics? Agents that inhibit parasympathetic nerves

Answer 5

also called cholinergic antagonists or cholinoceptor blockers.

Question 6

Give examples of muscarinic receptor antagonists.

Answer 6

hyoscine Atropine

Question 7

What is the role of sympathomimetics? They stimulate sympathetic nerves and mimic the effects of noradrenaline

Answer 7

also known as adrenergic agonists.

Question 8

List examples of indirectly acting sympathomimetics.

Answer 8

amphetamine Tyramine

Question 9

What are direct α and β agonists?

Answer 9

Direct agonists that stimulate both α and β adrenoceptors include noradrenaline and adrenaline.

Question 10

Define sympatholytics.

Answer 10

Agents that inhibit the effects of sympathetic nerve stimulation also known as adrenergic antagonists.

Question 11

Name an example of a catecholamine analogue used as a sympatholytic.

Answer 11

α-Methyldopa which forms α-methyl noradrenaline

Question 12

What is the function of reserpine?

Answer 12

It blocks the uptake of noradrenaline into vesicles causing degradation by monoamine oxidase (MAO).

Question 13

How does guanethidine act as a sympatholytic?

Answer 13

It displaces noradrenaline in vesicles and is then released as a “false transmitter.”

Question 14

List examples of direct α blockers.

Answer 14

Phentolamine phenoxybenzamine

Question 15

What are anti-histamines?

Answer 15

Agents that block histamine receptors divided into H1 and H2 blockers.

Question 16

Provide examples of H1 receptor blockers.

Answer 16

Promethazine chlorpheniramine

Question 17

What are anti-cholinesterase (Anti-ChE) drugs?

Answer 17

Drugs that inhibit acetylcholinesterase leading to accumulation of acetylcholine at cholinergic receptors.

Question 18

What are organophosphates?

Answer 18

Compounds like sarin and malathion that enhance acetylcholine effects at nicotinic receptors at NM junctions.

Question 19

What is the function of monoamine oxidase (MAO) inhibitors? To prevent the breakdown of neurotransmitters like catecholamines in nerve terminals and liver.

Question 20

List examples of MAO inhibitors.

Answer 20

Pargyline selegiline

Question 21

What are catechol-O-methyltransferase (COMT) inhibitors?

Answer 21

Enzyme inhibitors that prevent the breakdown of catecholamines though rarely used due to toxicity.

Question 22

Name a commonly used COMT inhibitor that crosses the blood-brain barrier.

Answer 22

Entacapone

Question 23

What is the function of adrenergic neuron blockers?

Answer 23

They prevent the release of noradrenaline at adrenergic nerve terminals.

Question 24

What are indirect sympathomimetics known for?

Answer 24

They enhance noradrenaline release or prevent re-uptake prolonging its action at neuroeffector junctions.

Question 25

How does cocaine act as a sympathomimetic?

Answer 25

It prevents noradrenaline re-uptake thereby prolonging its action.

Question 26

What are catecholamines?

Answer 26

A class of neurotransmitters including dopamine noradrenaline

Question 27

Which neurotransmitters act as local hormones or autacoids?

Answer 27

Histamine serotonin

Question 28

List the neurotransmitters that function as amino acids in the CNS.

Answer 28

Glutamate GABA

Question 29

What are peptide neurotransmitters?

Answer 29

Endorphins opioids