ANS I and II lectures

Question 1

what organs are only innervated by the sympathetic nervous system?

Answer 1

sweat glands, piloerector muscle, most peripheral blood vessels

Question 2

which nervous system is more active at rest?

Answer 2

parasympathetic is more active than sympathetic, though sympathetic is still active

Question 3

Where in spine is SNS sourced?

Answer 3

thoracolumbar region

Question 4

what pathways does SNS use to transmit information?

Answer 4

2 neuron pathway with end adrenergic receptor, the 2 neuron pathway with muscarinic receptor, and the one neuron pathway via the medulla

Question 5

describe the two 2 neuron pathways of the SNS

Answer 5

brain - preganglionic synapses at ganglion with acetylcholine and nicotinic receptor. postganglionic with NE or epi at adrenergic receptor.
2. brain: preganglion synapses at ganglion with acetylcholine and nicotinic receptor, postganglioniw with Ach at muscarinic receptor.

Question 6

what is length of neuron in SNS? PNS?

Answer 6

SNS: preganglion short because synapses close to vertebra. post ganglionic long.
PNS: pregangionic is long and postganglionic is short because ganglion close to target organ

Question 7

what is neuron pathway of PNS?

Answer 7

2 neuron system:

brain, preganglionic releases ACh at nicotinic receptor and postganglionic releases ACh at muscarinic receptor.

Question 8

ACh binds to two different receptors. What are they and how do they work?

Answer 8

Preganglionically, ACh binds to nicotinic receptor. Postganglionically, it binds to muscarinic receptor. The nicotinic receptor has no second messenger, whereas the muscarinic receptor is a G protein coupled receptor, so it has second messengers. It is therefore slower than the nicotinic receptor.