Spinal cord

Question 1

What does the spinal cord occupy?

Answer 1

C1- L1/L2 (vertebrae NOT segment)

Question 2

Cervical enlargement?

Answer 2

Contains nerve fibers for the upper limbs

Question 3

Lumbar enlargement?

Answer 3

Contains nerve fibers for the lower limbs

Question 4

What is the purpose of the enlargements in the spinal cord?

Answer 4

There are more neurons

Question 5

Conus medullaris?

Answer 5

Tapered terminal end of the spinal cord

Question 6

Anterior median fissure?
Posterior medial sulcus?

Which is deeper

Answer 6

Anterior spinal artery is located in the anterior median fissure
PMS- not as deep on the post. side of spinal cord
anterior median fissure is deeper

Question 7

What are rootlets?

Answer 7

The post. rootlets join together to form the post. root

The ant. rootlets join together to form the ant. root

Question 8

Anterior roots and anterior rootlets contain what?

Answer 8

Axons of motor neurons

Question 9

Post. roots and post. rootlets contain what?

Answer 9

Axons of sensory neurons

Question 10

The post. and ant. roots join together to form what?

Answer 10

mixed spinal nerve –> post/ant. rami

Question 11

Where is the dorsal root/ spinal ganglion found?

Answer 11

dorsal/post. side

Question 12

The anterior root innervates what?

Answer 12

All muscles except intrinsic back muscles and skin of back which is the posterior/dorsal rami.

Question 13

The post. root innervates what?

Answer 13

somatic sensory of skin

Question 14

What is a spinal cord segment?

Answer 14

A piece of the spinal cord associated with a pair of spinal nerves

Question 15

How many sacral spinal nerves? Thoracic nerves? Lumbar nerves?

Answer 15

(pairs)
1.) 8 cervical
2.) 12 thoracic
3.) 5 lumbar
4.) 5 sacral
5.) 1 coccygeal

Question 16

Which section of the vertebrae is there not a plexus? Why?

Answer 16

Thoracic, no room between ribs for the IC nerves

Question 17

Gray matter has what 2 horns and what do they house?

Answer 17

Post./dorsal horn- cell body of sensory neuron
Ant./ventral horn- cell body of motor neuron

Question 18

What does the lateral horn house? Where is it found?

Answer 18

SEGMENTS
T1-L1/2- cell body of the sympathetic motor neurons

S2-S4 - cell body of parasympathetic motor neurons

Question 19

What 3 columns is the white matter divided into?

Answer 19

1.) Dorsal column
2.) Lateral column
3.) Ant. column

mylinated nerve fibers

Question 20

Ant. white commissure?

Answer 20

bundle nerve fibers which cross the midline of the spinal cord just ant. to the gray commissure.