Lecture 18

Question 1

Where do the sympathetic nerves originate?

Answer 1

Sympathetic nerves originate from the T1-L2 levels of the spinal cord

Question 2

Where do the parasympathetic nerves originate?

Answer 2

Parasympathetic nerves originate from the CN’s 3, 7, 9, 10 and the S2-S4 levels of the spinal cord

Question 3

Describe the 2 neurons of the autonomic nervous system “2 neuron pathway”

Answer 3

Preganglionic neurons: always myelinated

Synapse with postganglionic neuron

Utilizes Ach (acetylcholine)

Postganglionic neurons: never myelinated

Originate from the ganglion

Generally utilizes norepinephrine

Question 4

True or False: preganglionic fibers synapse with the paravertebral ganglia. explain.

Answer 4

False

Preganglionic fibers DO NOT synapse with paravertebral ganglia but pass medially to synapse on preaortic ganglia

Question 5

Where are the preaortic ganglia located?

Answer 5

Preaortic ganglia are located near the origins of the major arterial branches from the abdominal aorta

Question 6

what structures link the preaortic ganglia to their target organs?

Answer 6

Postganglionic fibers travel from the preaortic ganglia to their target organs by following the arterial branches

Question 7

Describe the splanchic nerves in terms of what they are composed of, where they synapse and what structures they supply

Answer 7

Splanchic nerves are composed of preganglionic fibers and visceral sensory fibers, they synapse in the prevertebral ganglia, and supply the abdominal viscera