6 - Autonomic Pharmacology 1 Flashcards
what is the transmitter in the preganglionic neurones of the sympathetic and parasympathetic fibres
always acetyl choline
what is the neurotransmitter in the postganglionic neurones for parasympathetic
ACh
what is the neurotransmitter in the postganglionic neurones for sympathetic
usually noradrenline
the sympathetic is the site of pre and post ganglionic synapse for spinal nerves ___ to ___
T1- L2
which neurones tend to be short in length for sympathetic
pre-ganglionic
the sympathetic supply to the adrenal gland is special as here is no ____ ____ neurone so only ___ is used as a transmitter
post ganglionic neurone, ACh
which nerves are responsible for parasympathetic outflow?
cranial nerve 3,7,9 and 10 and sacral spinal nerves
where does the synthesis of transmitter occur and what compounds make them
in the cytoplasm by enzymes
steps involved in neurochemical transmission
- Uptake of neurotransmitter ____ to the nerve _____
- synthesis of ____
- _____ of transmitter
- ______ by AP
- __ influx through VA __ channels
- __ induced release of transmitter - exocytosis
- ___ _____ on post-synaptic cell
- the transmitter is either _____ by enzymes or ____ __ by nerve terminal or non-neuronal cell
- Uptake of neurotransmitter precursor to the nerve terminal
- synthesis of transmitter
- storage of transmitter
- depolarisation by AP
- Ca influx through VA Ca channels
- Ca induced release of transmitter - exocytosis
- receptor activation on post-synaptic cell
- the transmitter is either inactivated by enzymes or re-taken up by nerve terminal or non-neuronal cell
presynaptic transmission in the sympathetic and division - ACh opens ___ - ____ ion channels (______ ACh receptors) -
ligand-gated ion channels (nicotinic ACh receptors)
sympathetic post synaptic- noradrenline activates __-_____ ___ _____ in the target cell to cause a cellular response
G-protein coupled adrenoceptors
parasympathetic postsynaptic - ACh activated ____ ___ ____ _____ _____ _____ in the target cell to cause a cellular response
G-Protein coupled muscarinic acetylcholine receptors
G protein ACh receptors are called what? and ligand gated Ach receptors are called what?
g protein called - muscarinic and ligand gated are nicotinic
There are __ _____ subunits that make up ligand gated ion channels
5 glycoprotein
what are the three components in g coupling receptors
receptor, G protein and effector (enzyme or ion channel)
signalling via __ ____ is relatively slow in comparison to ___ __ ion channels
G protein, transmitter-gated (ligand gated)
in the G protein mechanism the _____ is an integral membrane protein and the ___ is a peripheral membrane protein
receptor, G-protein
what is the structure of the receptor in G protein coupling
single polypeptide with extracellular NH2 and intracellular COOH termini
7 transmembrane spans
what is the structure of the G-protein in G protein coupling
consists of 3 polypeptide subunits (alpha, Beta, gamma)
which subunit of the G-protein in G-protein coupling contains a guanine nucleotide binding site that can hold GTP or GDP
alpha
G-protein - No signalling
- the receptor is unoccupied
- the G protein ____ subunit binds ___
- the effector is not modulated
alpha, GDP
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 ___
- 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
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
- 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
