CNS/PNS/ANS week 2

Question 1

In the CNS all the spinal nerve levels match with the corresponding vertebra with one exception. What is it?

Answer 1

there are 8 cervical nerves and the are above the corresponding vertebra.

Question 2

Why is spinal nerve C8 special?

Answer 2

it has no corresponding vertebrae and arrises below C7

Question 3

How many Cervical nerves?
thoracic?
lumbar?
Sacral?

Answer 3

CN 8
TN 12
LN 5
SN 5

Question 4

Where does the spinal cord proper end?

Answer 4

Between L1 and L2

Question 5

What are the 3 spinal cord meninges?

Answer 5

Dura-outermost
Arachnoid-In the middle (will have blood vessels)
Pia-most deep and covers brain and spinal cord tightly.

Question 6

Where is CSF in regards to the meninges?

Answer 6

in the subarachnoid space

Question 7

Where are dentate ligaments?

Answer 7

between the ventral and dorsal roots

Question 8

What types of neurons on in the ventral horn?
Lateral horn?
Dorsal horn?

Answer 8

Ventral= somatic motor neurons
Lateral= visceral motor neurons
Dorsal= secondary sensory somatic and visceral neurons.
*primary sensory somatic and visceral neurons cell bodies are in the dorsal root ganglion(DRG)

Question 9

Why does the thoracic spinal cord have less grey matter?

Answer 9

not very much motor or sensory function from those nerves.

Question 10

Why is there a lot more white matter in the cervical regions of the spinal cord?

Answer 10

There are more axons and thus myelination giving more white matter as you move superiorly

Question 11

3 main parts of spinal nerves and characteristics of each

Answer 11

roots-one way streets (D.A.V.E)
trunk-two way traffic
rami-two way traffic (sensory and motor)

Question 12

Ventral rami serve what body parts?

Answer 12

body wall and limbs

Question 13

Dorsal rami serve what body parts?

Answer 13

serve deep back muscles and skin on back

Question 14

sympathetic ANS

Answer 14

fight or flight- arteries to smooth muscles will constrict to allow more flow to viscera

Question 15

Parasympathetic ANS

Answer 15

rest and digest-visceral organs to begin working and limbs will have decreased blood flow.

Question 16

sympathetic pre-ganglionic neuron origins

Answer 16

from T1 - L2 ONLY

Question 17

Parasympathetic pre-ganglionic neuron origins

Answer 17

on the brain stem
and S2-S4 innervate hindgut (descending colon thru anus), pelvic organs and perineum. *everything else is from the brain stem!!**

Question 18

Neural crest cells (post-ganglionic sympathetic neurons)

Answer 18

become peripheral nerve ganglia

1. dorsal root ganglion

Question 19

Neural crest cells migration in front of notochord ganglia name (post-ganglionic sympathetic neurons)

Answer 19

paravertebral ganglia

this is the sympathetic chain

Question 20

Neural crest cell migration in front of aorta ganglia name (post-ganglionic sympathetic neurons)

Answer 20

preaortic ganglia or prevertebral ganglia

Question 21

Neural crest cell migration in front of viscera (post-ganglionic parasympathetic neurons)

Answer 21

Intramural ganglia

Question 22

White rami

Answer 22

preganglionic sympathetics traveling between the spinal cord and the paravertebral chain

Question 23

Grey rami

Answer 23

pre and post-ganglionic sympathetics traveling to the periphery

Question 24

Sensory pathways for ANS

Answer 24

follow the same route as motor but have no synapses until in dorsal root ganglia