6 - Autonomic Pharmacology 1

Question 1

what is the transmitter in the preganglionic neurones of the sympathetic and parasympathetic fibres

Answer 1

always acetyl choline

Question 2

what is the neurotransmitter in the postganglionic neurones for parasympathetic

Answer 2

ACh

Question 3

what is the neurotransmitter in the postganglionic neurones for sympathetic

Answer 3

usually noradrenline

Question 4

the sympathetic is the site of pre and post ganglionic synapse for spinal nerves ___ to ___

Answer 4

T1- L2

Question 5

which neurones tend to be short in length for sympathetic

Answer 5

pre-ganglionic

Question 6

the sympathetic supply to the adrenal gland is special as here is no ____ ____ neurone so only ___ is used as a transmitter

Answer 6

post ganglionic neurone, ACh

Question 7

which nerves are responsible for parasympathetic outflow?

Answer 7

cranial nerve 3,7,9 and 10 and sacral spinal nerves

Question 8

where does the synthesis of transmitter occur and what compounds make them

Answer 8

in the cytoplasm by enzymes

Question 9

steps involved in neurochemical transmission

1. Uptake of neurotransmitter ____ to the nerve _____
2. synthesis of ____
3. _____ of transmitter
4. ______ by AP
5. __ influx through VA __ channels
6. __ induced release of transmitter - exocytosis
7. ___ _____ on post-synaptic cell
8. the transmitter is either _____ by enzymes or ____ __ by nerve terminal or non-neuronal cell

Answer 9

1. Uptake of neurotransmitter precursor to the nerve terminal
2. synthesis of transmitter
3. storage of transmitter
4. depolarisation by AP
5. Ca influx through VA Ca channels
6. Ca induced release of transmitter - exocytosis
7. receptor activation on post-synaptic cell
8. the transmitter is either inactivated by enzymes or re-taken up by nerve terminal or non-neuronal cell

Question 10

presynaptic transmission in the sympathetic and division - ACh opens ___ - ____ ion channels (______ ACh receptors) -

Answer 10

ligand-gated ion channels (nicotinic ACh receptors)

Question 11

sympathetic post synaptic- noradrenline activates __-_____ ___ _____ in the target cell to cause a cellular response

Answer 11

G-protein coupled adrenoceptors

Question 12

parasympathetic postsynaptic - ACh activated ____ ___ ____ _____ _____ _____ in the target cell to cause a cellular response

Answer 12

G-Protein coupled muscarinic acetylcholine receptors

Question 13

G protein ACh receptors are called what? and ligand gated Ach receptors are called what?

Answer 13

g protein called - muscarinic and ligand gated are nicotinic

Question 14

There are __ _____ subunits that make up ligand gated ion channels

Answer 14

5 glycoprotein

Question 15

what are the three components in g coupling receptors

Answer 15

receptor, G protein and effector (enzyme or ion channel)

Question 16

signalling via __ ____ is relatively slow in comparison to ___ __ ion channels

Answer 16

G protein, transmitter-gated (ligand gated)

Question 17

in the G protein mechanism the _____ is an integral membrane protein and the ___ is a peripheral membrane protein

Answer 17

receptor, G-protein

Question 18

what is the structure of the receptor in G protein coupling

Answer 18

single polypeptide with extracellular NH2 and intracellular COOH termini

7 transmembrane spans

Question 19

what is the structure of the G-protein in G protein coupling

Answer 19

consists of 3 polypeptide subunits (alpha, Beta, gamma)

Question 20

which subunit of the G-protein in G-protein coupling contains a guanine nucleotide binding site that can hold GTP or GDP

Answer 20

alpha

Question 21

G-protein - No signalling

• the receptor is unoccupied
• the G protein ____ subunit binds ___
• the effector is not modulated

Answer 21

alpha, GDP

Question 22

G-protein - turning on the signal

• agonist binds
• G -protein couples with ____
• ___ dissociates from the __ subunit and ___ binds to it
• G -protein ____ into __ and ___ subunits
• G-protein ___ subunit combines with and modifies the ___

Answer 22

• agonist binds
• G -protein couples with receptor
• GDP dissociates from the alpha subunit and GTP binds to it
• G -protein dissociates into alpha and beta,gamma subunits
• G-protein alpha subunit combines with and modifies the effector

Question 23

G-protein - turning off the signal

• The ___ subunit acts as an ____ (a _____) to hydrolyse ___ to ___ and __
• the G protein alpha subunit recombines with the ___ subunit

Answer 23

• the alpha subunit acts as an enzyme (a GTPase) to hydrolyse GTp to GDP and Pi so the signal is turned off

the G protein alpha subunit recombines with the beta, gamma subunit