Autonomics

Question 1

Autonomic NS: Which are myelinated, pre ganglionic axons or post ganglionic axons?

Answer 1

Pre ganglionic only.

Question 2

Parasympathetic outflow:

1. What two places?
2. Explain what nerves/areas invovled

Answer 2

1. Brainstem, or sacral
2. Brainstem:
   CAT nerves (III, VII, IX, X)
   sacral: S2-S4

Question 3

Sympathetic outflow: Where is it?

Answer 3

T1-T12, and L1-L2

Question 4

Parasympathetic outflow: Which nerves go where?

Answer 4

CN III, VII, IX- Head
CN X- Neck to midgut
S2-4- hindgut and pelvic viscera

Question 5

What type of smooth m. do parasympathetics innervate?

Answer 5

Non vascular, meaning they are smooth muscle tubes and bags NOT filled w/blood.

Question 6

How do sympathetic axons leave the spinal cord?

Answer 6

From lateral horn of T1-L2 to ventral ramus to white ramus communicans to sympathetic chain ganglion

Question 7

Where is the only place white ramus communicans are found?

Answer 7

T1-L2, because that’s where the sympathetic innervation has to leave the spinal cord.

Question 8

Sympathetics: If target is body wall, where will the nerve travel from the sympathetic chain ganglion?

Answer 8

gray ramus communicans to the mixed spinal nerve, and then go from there.

Question 9

sympathetics: If the target is a body wall organ, how does the innervation leave CNS?

Answer 9

1. Leave CNS, synapse in chain at same level, then go through gray ramus communicans to MIXED spinal nerve
2. Leave CNS, travel up or down chain and synapse elsewhere in the chain, then through gray ramus communicans to MIXED spinal nerve.

Question 10

Sympathetics: If target is in the body cavity distribution, how does the innervation leave CNS?

Answer 10

CANT TAKE SPINAL NERVE OR GRAY RAMUS COMMUNICANS.

1. Leave CNS, synapse in chain, go to target
2. Leave CNS, NO synapse in chain, take splanchnic nerve to go to pre aortic ganglion and synapse, then go to target