Anatomy of Autonomics

Question 1

General visceral motor division of PNS

Answer 1

Motor neurons regulating smooth muscle, cardiac muscle and glands.
Regulates heart beat, BP, digestion, urination.

Question 2

General visceral sensory division of PNS

Answer 2

Monitor sensations within visceral organs: stretch, temp. changes, chemical changes and irritation.
No pain when visceral organs are cut - pain is from chemical irritation or inflammation.
Pain is perceived as from somatic origin.

Question 3

Sympathetic overview

Answer 3

Catabolic.
Distributed to all vascularized areas of body
Responsible for vasoconstriction.

Question 4

Parasympathetic overview

Answer 4

Anabolic.
Promotes normal function.
Restricted to head, neck, body cavities, and genitalia.
ALL glandular secretion is from PSNS except for sweat glands.

Question 5

Comparative length of neurons

Answer 5

SNS presynaptic neurons are short and postsynaptic neurons are long. Influence many organs at once.
PSNS presynaptic neurons are long and synapse in the target organ. Localized affect.

Question 6

NT release from SNS:

PSNS:

Answer 6

NE, adrenergic.

Ach, cholinergic.

Question 7

White vs. grey rami communicans

Answer 7

White bring signal from SC to the sympathetic chain.

Grey bring signal from sympathetic chain to re-enter the spinal nerve.

Question 8

White rami communicans are found:

Answer 8

Only at T1 to L2/3 because presynaptic neurons are only found here.

Question 9

Grey rami communicans are found:

Answer 9

From C1 to Co1 because SNS innervation must go everywhere.

Question 10

Role of the adrenal medulla in sympathetic division

Answer 10

T8-L1 SNS preganglionic fibers synapse on medullary chromaffin cells which stimulates adrenaline release.
This is the exception to the 2 neuron pathway of the ANS.

Question 11

Overview of the PSNS division

Answer 11

Cranial division is of 4 CNs. Scaral division from S2-S4.

Axons run in ventral roots out via ventral rami.

Question 12

Sacral outflow of the PSNS form:

Answer 12

Pelvic splanchnic nerves distrubuted via inferior hypogastric plexus to the viscera where they synapse with postsynaptic neurons within the organs.

Question 13

Enteric NS

Answer 13

Consists of neurons distributed in the wall of the GI tract from esophagus to anus.
Can be capable of ANS function. Includes postsynaptic neurons for vagus n. and pelvic splanchnic ns.