Exam 2

Question 0

spinal cord diamiter

Answer 0

1.3cm max
@ C5-6 cord level
(75% vertebral canal)

Question 1

spinal cord length

Answer 1

40-45cm

16-18in.

Question 2

spinal cord weight

Answer 2

1 oz
27-35 grams
2% CNS weight

Question 3

superior boundary of spinal cord

Answer 3

foramen magnum

superior most ventral rootlet of 1st cervical spinal nerve

Question 4

inferior boundary of spinal cord

Answer 4

disc b/w vertebral levels L1-2

Question 5

of spinal nerve pairs

Answer 5

31

Question 6

Dorsal roots contain —- fibers

Ventral roots contain —- fibers

Answer 6

sensory (afferent)

motor (efferent)

Question 7

at birth the Co1 cord level is at the same level as —- vertebra

Answer 7

L1-3

Question 8

by adulthood the Co1 cord level is found at —- vertebral level

Answer 8

L1-2

Question 9

name of tapering end of the spinal cord

Answer 9

conus medullaris

Question 10

rexed lamina 1

Answer 10

thin cap over dorsal horn

Question 11

rexed laminal 2

Answer 11

pain

“substantia gelatinsoa”

Question 12

rexed lamina 3&4

Answer 12

sensory info

“nucleus proprius”

Question 13

rexed lamina 5

Answer 13

cervical level: “reticular formation”

continuous with midbrain and pons

Question 14

rexed lamina 6

Answer 14

missing at some levels

Question 15

rexed lamina 7

Answer 15

many descending tract fibers synapse w/ neurons in this lamina

Clarke’s nucleus: C8-L3, contribute axons to P. spinocerebellar tract

Question 16

rexed lamina 8

Answer 16

med aspect of anterior horn

Question 17

rexed lamina 9

Answer 17

Class A alpha motor neurons are abundant here

skeletal muscles are motor innervated from neurons in this lamina

Question 18

rexed lamina 10

Answer 18

surrounds the central canal and contains the anterior and posterior gray commissures

Question 19

Neuroglial support and covering cells. Especially —— which form myelin and give the white appearance to white matter

Answer 19

interfascicular oligodendrocytes

Question 20

Fasciculi are found w/i ——

Answer 20

funiculi

Question 21

fasciculi fibers associate with one another by ——– during development and thus remain together. the molecules that accomplish this are named ——–

Answer 21

surface proteins

NCAM’s (nerve cell adhesion molecules)

Question 22

DRG’s average b/w ——– neurons

Answer 22

(dorsal root ganglion)

50k-100,000

Question 23

secondary axons in fasiculi from dorsal gray neurons
go to the ventral horn of that ———
cross to an opposite horn at the ——-

Answer 23

original segment

same segment level

Question 24

secondary axons in fasiculi from dorsal gray neurons

some run b/w cord segment levels (—–). _________ axons may be ipsi or contralateral

Answer 24

intersegmental

Question 25

secondary axons in fasiculi from dorsal gray neurons
some fibers may project to higher brain centers. these fibers are often associated together to form the functional groups ——-

Answer 25

ascending fasciculi

Question 26

secondary axons in fasiculi from dorsal gray neurons

——- would be fibers from higher brain centers descending to generally end in the cords lamina 7,8,and 9

Answer 26

descending fasciculi

Question 27

ascending cord fasciculi tracts

Answer 27

gracilis
cuneatus
post. and ant. spinocerebellar
ant. and lateral spinothalamic

Question 28

descending cord fasciculi tracts

Answer 28

lat. and ant. corticospinal
lat. and med. reticulospinal
vestibulospinal
rubrospinal
tectospinal

Question 29

posterior column fasciculi

Answer 29

gracilis and cuneatus

Question 30

gracilis cord levels

Answer 30

all

Question 31

cuneatus cord levels

Answer 31

above T6

Question 32

functions of gracilis and cuneatus

Answer 32

2pt touch
vibratory
kinesthetic
(particularly from distal parts of extremities)

Question 33

test for posterior spinal tracts
(most commonly misinterpreted test)
“visual, vestibular, proprioceptive”

Answer 33

Romberg’s test