M+R Session 10- The ANS Flashcards
What is the origin of the sympathetic nervous system?
Thoraco-lumbar
What is the origin of the parasympathetic nervous system?
Cranio-sacral
What is the neurotransmitter present at all preganglionic neurones?
Acetylcholine
What is the neurotransmitter present at the postganglionic neurone at each nervous system?
Sympathetic- noradrenaline
Parasympathetic- acetylcholine
What is the sympathetic postganglionic neurones neurotransmitter in adrenal glands?
Chromaffin cells
What are the receptors that act on the heart? (2)
Beta 1 and M2
What are the receptors that are found in vascular smooth muscle?
Alpha 1 and M3
What are the receptors found at the lungs?
Beta 2 and M3
Which enzyme is required for the production of acetylcholine?
Choline acetyl transferase (CHAT)
What is the enzyme required for the breakdown of acetylcholine?
Acetylcholinesterase
Why are unwanted side effects a result of muscarinic receptor activation?
Because agents that bind to these receptors are not selective towards them.
Which step of noradrenaline synthesis occurs in the vesicles in the preganglionic neurone?
Dopamine-> noradrenaline via dopamine beta hydroxylase enzyme.
What do Chromaffin cells release?
Adrenaline, into the bloodstream
Where are noradrenaline containing vesicles found in the preganglionic neurone?
Varicosities
How is noradrenaline removed from the synaptic cleft?
Via a reuptake system:
- uptake 1- NA is taken up into the pre-synaptic terminal by a sodium dependent transporter.
- uptake 2- any remaining NA is taken up by a lower affinity mechanism.
