Lecture 2: Autonomic Nervous System Flashcards
What components does the preganglionic fiber link?
CNS to ganglion
What components does the postganglionic fiber connect?
Ganglion to gland cells, smooth muscle cells and cardiac muscle cells
Where does the output leave the spinal cord in the parasympathetic division?
At cranial and sacral regions
Where does the output leave the spinal cord in the sympathetic division?
It runs all the way down the spinal cord
What is the structure of acetylcholine?
Has a permanent positive charge
Has ester linkage
What are the two types of acetylcholine receptor?
Nicotinic and muscarinic
What are some features of nicotinic receptors?
- Pentameric
- 16 subunits
- Many subtypes
- Built in ion channels
- 2+ ACh sites
- Responses µs-ms
What are some features of muscarinic receptors?
- Monomeric
- M1-5 subtypes
- 5 Receptor types
- Binding site for G proteins
- 1 ACh site
- Responses ms-s
What are the agonists of nitotinic receptors?
Nicotine and Suxamethonium
What are the antagonists of nicotinic receptors?
Atracurium and tubocurarine
What are the agonists of muscarinic receptors?
Muscarine and Pilocarpine
What are the antagonists of muscarinic receptors?
Atropine and Hyosine
What is the process of the cholinergic terminal?
- Signal activates voltage gated calcium ion channels to open
- Calcium enters pre synaptic terminal
- Vesicles containing ACh fuse with membrane
- ACh diffuses across membrane and interacts with receptors
What is the processing of recycling choline?
- Leftover choline is taken back up to the nerve terminal by a carrier
- Its made back into ACh by enzyme choline acetyl transferase
- New ACh put into vesicles ready for release
Which parts of the nervous system are nicotinic receptors associated with?
NMJ, CNS and Autonomic ganglia
Which parts of the nervous system are the muscarinic receptors associated with?
CNS, Parasympathetic and Sympathetic
What are the different subtypes of muscarinic receptors?
M1 M2 M3 M4 M5
What is the location of M1?
Glands
Cerebral cortex
Autonomic ganglia
What is the pathway of M1?
IP3 (Gq)
What are the selected roles of M1?
Cognition (not fully known)