Sympathetic NS Flashcards
Where do the preganglionic sympathetic axons entering sympathetic chains terminate?
- Paravertebral sympathetic chains
- Prevertebral ganglia/plexuses
- Adrenal medulla
What do sympathetic axons look like?
In general preganglionic fibres are short & postganglionic fibres are relatively long
Where do the sympathetic axons run in the paravertebral sympathetic chains?
Both pre- and postganglionic axons may run for some distance up or down the sympathetic chain before forming synapse/emerging
Where do the sympathetic axons run in the pre vertebral ganglia/plexuses?
In the abdominal cavity: 3 main;
- Coeliac ganglion
- Superior mesenteric ganglion
- Hypogastric (or inferior mesenteric) ganglion
Chromatin cells analogous to sympathetic ganglia cells
Whatever this means
Where are NTs released from on the ganglions?
They are released from the varicosities r
What NT do most sympathetic postganglionic neurone use?
Noradrenaline - which bind to adrenoreceptors
How is noradrenaline produced?
From tyrosine
Enzyme tyrosine hydroxyls breaks this down
How many types of adrenoreceptors are there?
2
alpha & beta
What happens to noradrenaline after it has been released into the synapse?
It is removed via reuptake in both pre and postsynaptic membrane
NA reincorporated into vesicles –> called transmitter economy
What is an enzyme that can also breakdown noradrenaline?
Enzyme Monoaminoxidase (MAO)
What is transmitter economy?
When NTs are reincorporated into vesicles - taken back up
What is the feedback loop involved with noradrenaline?
The feedback loop is where there is an alpha receptor on the presynaptic controls the amount of NA taken up
What sort of receptors are alpha and beta adrenoreceptors?
Metabotrophic receptors
They wind back and forth in and out of cell membrane in 7 chains
When noradrenaline is released
