lecture 8 Flashcards
What does cholinergic mean?
Via acetylcholine.
Joined by an ester bond
Describe the cholinergic transmission.
Same as action potential process.
Acetylcholinesterase breaks down into acetate and choline.
How is choline recycled?
Back in pre synaptic terminal. Choline acetyl transferase.
Taken back to vesicles.
Describe muscarinic receptors
G protein coupled, slow
Found in CNS, parasympathetic And sympathetic
Describe nicotinic receptors
Ligand gated ion Channel, fast transmission.
Neuro muscular junctions, CNS, autonomic ganglia.
What is a catechol group?
Benzene ring with two OH groups adjacent.
Describe a noradrenergic synapse?
Same as ACh up to fuse with post synaptic membrane, but not broken down.
Reuptaken into pre synaptic.
Describe the biosynthesis of adrenaline.
Lecture 8 jeez.
What enzymes break down adrenaline?
Monoamine oxidase (MAO) Catechol-O-methyl transferase (COMT)
Describe adrenocepors
Alpha and beta, more subtypes now defined.
What is a ganglion?
Collection of cell bodies ess outside the cns
Describe the organisation of the sympathetic nervous system.
Neuron from spinal cord sends axon to another neuron - ganglion. ACh is the nt, nicotine acetylcholine receptors.
Neuron then goes to target tissue, releases mostly noradrenalin, some adrenaline, act on adrenergic receptors.
What are the types of ganglia coming from the spinal cord?
First short neuron coming out is a paravertebral ganglia.
Further away is vertebral ganglia.
Describe the adrenal medulla.
Sympathetic
Derived from neuronal tissue.
ACh goes to nicotine receptors, adrenaline and noradrenaline released into the blood (4:1)
Describe the organisation of the parasympathetic system
ACh to nicotine ACh receptors on ganglion. At target tissue ACh to muscarinic ACh receptors.
What are the differences in the general organisation of para v sympathetic?
Para has longer axons in neuron going to ganglion since its closer to the target tissue.
Para always uses ACh at target tissue synapse.
Output of para from medullary and sacral regions (top and bottom).
Symp more even.
What is the vagus nerve?
Parasympathetic nerve, make synapses in Sino atrial node and release ACh. Bind to Muscarinic receptors, decrease heart rate.
What happens if atropine is added to the vagus nerve?
Antagonist to ACh, SA node fires at natural rate and heart rate increases.
Parasympathetic output from the spinal cord is confined to the following regions:
medullary and sacral
