4-Autonomic Nervous System

Question 1

Generally describe the autonomic nervous system

Answer 1

aka visceromotor, involuntary, efferent only

Question 2

How many cells are required for autonomic transmission

Answer 2

two (preganglionic and post ganglionic)

Question 3

What parts of the autonomic system are myelinated

Answer 3

only pregangionic fibers

Question 4

T/F Autonomic is only excitory

Answer 4

False, autonomic is both excitatory and inhibitory

Question 5

Name effector organs of the ANS

Answer 5

cardiac muscle, glands, smooth muscle (although effector organs do not need ANS to function)

Question 6

What is autonomic tone?

Answer 6

both the sympathetic and parasympathetic working together, working at same time to varying degrees

Question 7

Where do the sympathetic originate?

Answer 7

T1-L2 and brainstem/S2-S4 respectively

Question 8

What are the destinations of the sym/para respectively?

Answer 8

organs and body wall/ only body wall

Question 9

Which sym/para has the longest preganglionic fibers

Answer 9

parasympathetic

Question 10

Where are the cell bodies of the sympathetic located

Answer 10

lateral horn and the sympathetic chain ganglia

Question 11

What neurotrasmitter do the presynaptic fibers use?

Answer 11

Ach

Question 12

What neurotrasmitter do the postsynaptic fibers use

Answer 12

symp (NE or Ach) para (Ach only)

Question 13

Describe the sympathetic chain

Answer 13

aka sympathetic trunk, runs the length of vertebral column, chain ganglia contain post ganglionic cell bodies

Question 14

What are the two types of communicating rami

Answer 14

white (IN to the chain, myelinated preganglionic, T1-L2) and gray (OUT of the chain, unmyelinated postganglionic, at all spinal nerve)

Question 15

Describe generally the parasympathetic system

Answer 15

aka craniosacral, brainstema dn lateral horn of S2-4, go to organs only, possess terminal ganglia near the near or part of the termal organ

Question 16

Name cranial nerves involved in the para

Answer 16

3, 7, 9 and 10 (vagus)

Question 17

What does the vagus nerve innervate

Answer 17

thoracic organs as well as the foregut and part of hind gut

Question 18

Trace the sym pathway from nerve cell bodies to target tissue in body wall

Answer 18

lateral horn, white communicating rami, chain ganglia, gray rami, and dorsal/vental nerve

Question 19

How do sympathetic pathways reach the head or lower limbs

Answer 19

enter the white rami at initial spinal level then travel higher or lower on the chain and exit a gray rami to form nerve

Question 20

Describe the pathway of symp thoracic organs

Answer 20

ventral horn, ventral rami, white rami to chain and straight to cervical splanchnic nerve (3) to heart and lungs

Question 21

Describe the symp pathway to the abdominal organs

Answer 21

ventral horn, white ramus, through chain, cell body in collateral ganglion as part of the thoracic splanchnic nerve (3), stomach+

Question 22

Which pathway of the sym has only one neuron

Answer 22

innervation of the adrenal medulla

Question 23

Name the terminal nerve that include a collateral ganglia

Answer 23

thoracic splanchnic and lumbar/sacral splanchnic

Question 24

Where are collateral ganglia located

Answer 24

on the aorta

Question 25

Describe the path of the vagus nerve

Answer 25

made of preganglionic, L/R descend thru neck and bsend branches to cardiopulmonary plexus, break up to form the esophageal plexus before coalescing to cross the diapragm where they innervate foregut and midgut

Question 26

Where anterior/ posterior do the L/R vagus end up

Answer 26

L- anterior to vagal trunk, R- posterior vagal trunk

Question 27

Describe the pelvic splanchnic

Answer 27

parasympathetic that leave S2-4 via the ventral rami and innervate the hindgut and pelvic organs (digestion, urnation (etc) and sexual arousal)

Question 28

Describe the path of para pathway to pelvic organ

Answer 28

lateral horn, ventral root to ventral ramus, pelvic splachnic nerve to terminal ganglion on organ

Question 29

What are visceral afferents?

Answer 29

sensory nerves from the organs-stretch, baro and chemo receptor, not part of ANS, rarely reaches conscious levels

Question 30

Describe the path of visceral afferent pathways

Answer 30

back track with autonomic pathway until spinal nerve then exit to ventral horn and synapse on dorsal horn, with cell bodies in the DRG

Question 31

Why is referred pain an issue with viscerosensory?

Answer 31

there is cross-talk with somatic sensory because they both go to the dorsal horn

Question 32

What are visceral reflex

Answer 32

visceral sensation results in visceral/somatic effects ie. Blood pressure or cough reflex