Lecture 17: Spinal Cord

Question 1

Dermatome

Answer 1

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

Question 2

Myotome

Answer 2

All the muscles that are innervated by a single efferent anterior root
-most muscles are composed of more than one myotome

Question 3

Pairs of spinal nerves
Cervical
Thoracic
Lumbar
Sacral
Coccygeal

Answer 3

8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

Question 4

Cervical enlargement

Answer 4

C3-T1

Question 5

Lumbar enlargement

Answer 5

L1-S2

Question 6

Cervical plexus

Answer 6

C1-C4

Question 7

Brachial plexus

Answer 7

C5-T1

Question 8

Lumbosacral plexus

Answer 8

L1-S4

Question 9

Posterior (dorsal) horns

Answer 9

Receive incoming sensory fibers

Question 10

Anterior (ventral) horns

Answer 10

Site of cell bodies of alpha motor neurons to skeletal muscle fibers

Question 11

Lateral horns

Answer 11

Site of cell bodies of autonomic neurons

Located only in thoracic and upper lumbar region

Question 12

White matter : Columns

Answer 12

Consist of myelinated tracts

Question 13

Spinal cord proper (Conus medullaris) ends at which level

Answer 13

L2

Question 14

Filum terminale

Answer 14

Extends from conus medullaris (L2) to coccyx

Question 15

Dorsal root carries

Answer 15

Afferent fibers

Question 16

Dorsal root ganglion is location of

Answer 16

Cell bodies of afferent neurons

Question 17

Ventral roots carry

Answer 17

Efferent fibers, no ganglion

Question 18

Spinal nerve carries

Answer 18

Afferent/efferent
Visceral/somatic
Proprioceptive

Question 19

Dorsal rami

Answer 19

To epaxial musculature (deep back muscles) and skin on either side of back

Question 20

Ventral rami

Answer 20

To hypaxial musculature and rest of skin

Question 21

White ramus communicans

Answer 21

Carries pre-ganglionic sympathetic fibers from lateral horns (thoracolumbar region)

Question 22

Gray ramus communicans

Answer 22

Carries post-ganglionic sympathetic fibers from paravertebral ganglia back to spinal nerve

Question 23

Meningeal coverings and space listed superficial-deep

Answer 23

Epidural space
Dura mater (tough outer layer)
Subdural space
Arachnoid
Subarachnoid space (Contains CSF)
Pia mater (delicate innermost layer)
Denticulate ligaments