Lecture 17: Spinal Cord

Question 1

What are the three regions of the somite?

Answer 1

dermatome
myotome
sclerotome

Question 2

What is a dermatome?

Answer 2

area of the skin supplied with afferent nerve fibers by a single posterior spinal root

Question 3

What is a myotome?

Answer 3

all the muscles that are innervated by a single efferent anterior root. Most muscles are composed of more than one myotome.

Question 4

Where is the cervical enlargement?

Answer 4

C3-T1

Question 5

Where is the lumbar enlargement?

Answer 5

L1-S2

Question 6

Where does the conus medullaris end?

Answer 6

L2

Question 7

Gray matter (horns) are equivalent to ____

Answer 7

CNS nuclei

Question 8

The posterior gray horns receive _____

Answer 8

incoming sensory fibers

Question 9

The anterior gray horns are the site of ____

Answer 9

cell bodies of alpha Moto neurons to skeletal muscle fibers

Question 10

The lateral gray horns are located in the _______ region and site of ______

Answer 10

thoracic and upper lumbar; cell bodies of autonomic neurons

Question 11

The white matter columns consist of ______

Answer 11

myelinated tracts

Question 12

The dorsal roots carry ____ fibers

Answer 12

afferent

Question 13

Ventral rootlets and root carries _____ fibers

Answer 13

efferent

Question 14

The spinal carries _____ fibers

Answer 14

both efferent and afferent

Question 15

Where does the dorsal primary rami go?

Answer 15

epaxial musculature and skin on either side of dorsal of back

Question 16

Where does the ventral primary rami go?

Answer 16

to hypaxial musculature and rest of skin

Question 17

What does the autonomic white ramus communicans carry?

Answer 17

pre ganglionic sympathetic fibers from lateral horns of central gray of spinal cord

Question 18

What does the autonomic gray ramus communicans carry?

Answer 18

post ganglionic sympathetic fibers from paravertebral ganglia back to spinal nerves

Question 19

What is the order of the meningeal coverings and spaces?

Answer 19

epidural space 
dura mater
subdural space
arachnoid 
subarachnoid space
pia mater
denticulate ligaments