autonomic nervous system

Question 1

what are the receptors in the sympathetic nervous system

Answer 1

adrenoceptors

Question 2

what are the receptors in the parasympathetic nervous system

Answer 2

cholinoceptors

Question 3

list the types and subtypes of adrenoreceptors

Answer 3

a1 (A, B and D) and a2 (A, B and C); B1 and B2

Question 4

list the two types of cholinoceptors

Answer 4

nicotinic and muscarinic

Question 5

name the two types of receptors

Answer 5

ion channel receptors and G-protein coupled receptors

Question 6

principle of ion channel receptors

Answer 6

rapid opening and closing upon ligand binding

Question 7

principle of G-protein coupled receptors

Answer 7

ligand binds and activates G protein, causing downstream effects; once activated effect can last for hours

Question 8

what type of receptor are pre-synaptic and post-synaptic receptors

Answer 8

regulatory

Question 9

nicotinic receptors in sympathetic nervous system: neurotransmitter and synapse

Answer 9

acetylcholine; pre-ganglionic to post-ganglionic in sympathetic chain, and in adrenal to effector organ synapse

Question 10

nicotinic receptors in parasympathetic nervous system: neurotransmitter and synapse

Answer 10

acetylcholine; pre-ganglionic to post-ganglionic synapse

Question 11

muscarinic receptors in sympathetic nervous system: neurotransmitter and synapse

Answer 11

acetylcholine; post-ganglionic to effector organ in sweat glands

Question 12

muscarinic receptors in parasympathetic nervous system: neurotransmitter and synapse

Answer 12

acetylcholine; post-ganglionic to effector muscle synapse

Question 13

cholinergic drugs: example of nicotinic receptor antagonist

Answer 13

tubocurarine

Question 14

cholinergic drugs: why is a nicotinic receptor antagonist like tubocurarine rarely used

Answer 14

as nicotinic receptors are also present at neuromuscular junctions, so would prevent inspiration etc.

Question 15

cholinergic drugs: effect of tubocurarine at nicotinic junctions and subsequent effect on respiration and heart rate

Answer 15

inhibits nicotinic junctions so causes a decrease in respiration and an increase in heart rate byremoving all autonomic control, causing a return to higher rate

Question 16

cholinergic drugs: example of competitive muscarinic receptor antagonist

Answer 16

atropine

Question 17

cholinergic drugs: effect of atropine on muscarinic receptors and subsequent effect on heart rate and sweat production

Answer 17

inhibits muscarinic receptors so increases heart rate as it blocks the action of parasympathetic nervous system, but decreases sweat production

Question 18

two examples of ion channel receptors

Answer 18

nicotinic receptors, ionotropic receptors

Question 19

where are ion channel receptors located

Answer 19

at all autonomic ganglia

Question 20

example of a g-protein coupled receptor

Answer 20

muscarinic receptors, adrenergic receptors

Question 21

what are g-protein coupled receptors stimulated by

Answer 21

all post-ganglionic parasympathetic neurones, and by sympathetic neurones at selected sites

Question 22

what type of receptor are adrenergic receptors

Answer 22

g-protein coupled receptors

Question 23

what is a1 receptor responsible for

Answer 23

smooth muscle contraction on effector organs

Question 24

what is a2 receptor responible for

Answer 24

pre-synaptic receptor inhibiting the release of noradrenaline

Question 25

what is B1 receptor responible for

Answer 25

post-synaptic receptor to increase cardiac output and heart rate

Question 26

what is B2 receptor responsible for

Answer 26

post-synaptic receptor to relax smooth muscle

Question 27

what drug targets a1 receptor and what is the effect

Answer 27

doxazosin, which acts as an a1 receptor antagonist causing smooth muscle dilation

Question 28

what drug targets a2 receptor and what is the effect

Answer 28

medotomidine, which acts as an a2 receptor agonist causing a decrease in noradrenaline release

Question 29

what drug targets B1 receptor and what is the effect

Answer 29

atenolol, which acts as a B1 receptor antagonist, decreasing cardiac output and heart rate

Question 30

what drug targets B2 receptor and what is the effect

Answer 30

salbutamol, which acts as a B2 receptor agonist, causing smooth muscle to relax