inside of the spinal cord - lecture 5

Question 1

gray matter

Answer 1

composed of neurons, their processes and neuroglia

gray d/t neuron cell bodies

Question 2

where is ratio greatest

Answer 2

in the mid to lower cervical and lumbar levels

d/t responsibility for appendicular control of UE and LE

Question 3

what is the appearance of gray matter

Answer 3

“butterfly wings”

Question 4

what’re the “butterfly wings” connected by

Answer 4

gray commissure

–> its center is occupied by the central canal

Question 5

what is gray matter divided into

Answer 5

ventral/anterior

dorsal/posterior

lateral columns/horns

Question 6

posterior horn

Answer 6

dorsal horn

dorsal gray matter of the spinal cord

contains interneurons

Question 7

where is info sent from the posterior horn

Answer 7

from receptors whose cell bodies lie in the dorsal root ganglion

skin, bone, joints

Question 8

anterior horn

Answer 8

ventral horn

contains interneurons and cell bodies of the large motor neurons that supply skeletal muscles (ventral root)

Question 9

cell bodies in the anterior horn

Answer 9

alpha or lower motor neurons

smaller gamma or fusimotor neurons

spinal accessory nucleus

phrenic nucleus

Question 10

alpha or lower motor neurons

Answer 10

skeletal muscles

Question 11

smaller gamma or fusimotor neurons

Answer 11

intrafusal fibers

Question 12

spinal accessory nucleus

Answer 12

that form accessory nerve

cervical region, neck innervations

Question 13

phrenic nucleus

Answer 13

motor neurons that innervate diaphragm

Question 14

lateral horn

Answer 14

intermediolateral

neurons are sympathetic motor neurons serving visceral organs

contain interneurons

Question 15

where do axons from the lateral horn exit from

Answer 15

via ventral root

Question 16

where does the lateral horn appear

Answer 16

only appears b/w T1-L2/L3

Question 17

white matter

Answer 17

made of myelinated/unmyelinated processes of neurons, neuroglia and blood vessels

white d/t myelin

Question 18

where is the ratio greatest for white matter

Answer 18

at cervical

Question 19

where is ratio lowest for white matter

Answer 19

at sacral

d/t number of ascending and descending nerve fibers increase in a rostral direction

Question 20

fxn of white matter

Answer 20

brings info into the CNS and transmits the info to higher levels

transmits info from the higher levels to the spinal cord and to muscles and glands

Question 21

how are nerves arranged

Answer 21

in bundles known as tracts (fasciculi)

Question 22

how are the nerves in white matter classified

Answer 22

3 categories

ascending

descending

intersegmental

Question 23

ascending nerves

Answer 23

sensory info to higher centers

Question 24

descending nerves

Answer 24

motor info to lower centers

Question 25

intersegmental

Answer 25

convey info b/w spinal cord segments

Question 26

white matter is subdivided into

Answer 26

3 major columns

dorsal funiculus

lateral funiculus

ventral funiculus

Question 27

dorsal funiculus

Answer 27

C1-T6 is further divided into

medial fasciculus gracilis

lateral fasciculus cuneatus

Question 28

ventral funiculus

Answer 28

home for ventral white commissure

Question 29

white commissure

Answer 29

region where decussation/crossing of the spinothalamic tract occurs