Lab Manual 4

Question 1

which vertebra level does the spinal cord end

Answer 1

level L1/L2

Question 2

where is the lumbar puncture located

Answer 2

L3-L5

Question 3

what are the spinal nerves?

Answer 3

small, white, cylindrical structures occurring in pairs about every 1.5 inches along the length of the cord

Question 4

denticulate ligaments

Answer 4

the short bands of fibrous pia mater extending along the spinal cord on each side, in-between the dorsal and ventral roots

Question 5

rootlets

Answer 5

small groups of axons that combine to form the nerve roots
- dorsal/posterior roots and ventral/anterior roots

Question 6

what do dorsal/posterior roots do

Answer 6

carry sensory impulses to the spinal cord

Question 7

what do ventral/anterior roots do

Answer 7

carry impulses from spinal cord to body

Question 8

where is the spinal cord thicker

Answer 8

at the neck and end of the cord (cervical and lumbar enlargements)

Question 9

why is the spinal cord thicker at the neck and end of the cord

Answer 9

large group of nerves leave the cord to seve the arms and legs

Question 10

where is there more gray matter than white matter in the spinal cord

Answer 10

s > l > t > c

Question 11

where is there more white matter than gray matter

Answer 11

c > t > l > s

Question 12

conus medullaris

Answer 12

the most caudal end of the spinal cord

Question 13

filum terminale

Answer 13

an inferior extension of the pia mater beyond the conus medullaris that anchors the spinal cord to the coccyx at the very bottom of the vertebral canal

Question 14

cauda equina

Answer 14

a bundle of spinal nerves - 2L - 5L, 1S - 5S, and the coccygeal nerve

Question 15

lumbar cistern

Answer 15

a subarachnoid space inferior to the conus medullaris
- cauda equina occupies it

Question 16

where are spinal taps conducted

Answer 16

lumbar cistern

Question 17

two subdivisions of autonomic nervous system

Answer 17

sympathetic nervous system, parasympathetic nervous system

Question 18

where are sympathetic neurons located

Answer 18

thoracic and upper lumbar spinal cord segments

Question 19

what do sympathetic neurons connect to

Answer 19

post-ganglionic neurons

Question 20

where are post-ganglionic neurons located

Answer 20

just outside of the vertebral column running in a connected chain along the bone column
- part of the PNS

Question 21

what do sympathetic chain ganglia neurons project to

Answer 21

target organs all over the body

Question 22

where are parasympathetic neurons located

Answer 22

in the brainstem and sacral spinal cord

Question 23

where do the parasympathetic neurons project

Answer 23

out of the CNS far away from the spinal cord to post-ganglionic neurons located near or in their target organs in the body

Question 24

where are parasympathetic post-ganglioni neurons found

Answer 24

in or near their target organs

Question 25

which parts of the spinal cord are white matter

Answer 25

dorsal, lateral, and ventral columns (aka posterior funiculus, lateral funiculus, and anterior funiculus)

Question 26

which parts of the spinal cord are gray matter

Answer 26

posterior (dorsal) horn, lateral horn (intermediate gray), & anterior (ventral) horn

Question 27

Westphal’s sign

Answer 27

the absence or decrease of the knee tap reflex; indicates spinal cord nerve damage

Question 28

what opposing muscles are required to produce the foot swing respose

Answer 28

contraction of the quadriceps and the inhibition of the opposing hamstring flexor muscle

Question 29

which spinal neurons mediate the knee jerk reflex

Answer 29

L2 - L4 spinal neurons

Question 30

two point distinction

Answer 30

the ability to discern that two nearby objects touching the skin are truly two distinct points, not one

Question 31

what is the medical use for two-point discrimination

Answer 31

testing for deficits in tactile perception and injury to the dorsal column medial lemniscus (DCML) ascending sensory neuron tracts