2-Organization Spinal Cord

Question 1

diameter difference

Answer 1

-cervical spinal cord enlargement bc inn the upper limb
-thoracic small diameter bc no nerve plexus
-lumber spinal cord enlarge bc inn lower limb

Question 2

gray matter

Answer 2

nerve cell bodies form ‘nuclei’

have dorsal horns (sensory) + intermediate zone (interneurons) + ventral horn (motor)
-in thoracic will also have lateral for ANS (pregang for sympathetic trunks)

Question 3

white matter

Answer 3

axons that form tracts/fasciculi/commissures

Question 4

lamination

general

Answer 4

I-X =laminae of rexed
I-VI = nociception, thermal, light/crude touch
VII = interneurons, proprioception
VIII-IX = motor
X = ANS

Question 5

laminae of rexed

specific

Answer 5

I = dorsomarginal nucleus
II = SG
III + IV = nucleus proprius
V = neck of dorsal horn with axon bundles
VI = base of dorsal horn for withdrawal reflex
VII = intermediate
VIII = motor
IX= motor
X = ANS

Question 6

location of autonomics

Answer 6

1. intermediolateral nucleus @ T1-L2/3, pregang SYMPATHETIC
2. sacral parasympathetic nucleus @S2-4, pregang PARASYMP

Question 7

white matter organization

Answer 7

1. dorsal funiculus/post column
2. dorsolateral funiculus
3. lateral funiculus/lateral column
4. ventrolateal funiculus
5. ventral funiculus/anterior column

Question 8

dorsal funiculus

Answer 8

two parts
1. fasciculus gracilis (medial) all levels, lower trunk/limb
2. fasciculus cuneatus (lateral) from C1-T6, upper trunks/limb

Question 9

lateral funiculus

Answer 9

has lateral corticospinal tract for motor/voluntary movement
-prominent in C levels, small in L

and has dorsal/ventral spinocerebellar tract for position

and spinothalamic tract for pain and temp

Question 10

dorsolateral tract

Answer 10

of lissauer - for pain and temp

Question 11

ventral white commissure

Answer 11

where axons cross at

Question 12

white matter levels

Answer 12

most whtie matter in cervical bc descending tracts thin as axons exit + ascending tracts thicken

leaste in lumbar

Question 13

quadriplegia

Answer 13

transection of spinal cord at upper cervical levels so loss of sensation and motor function below level of lesion

Question 14

paraplegia

Answer 14

transection of spinal cord at thoracic levels so loss sensation and motor to lower limbs

Question 15

T12/L1 relevance

Answer 15

lower lumber and all sacral spinal cord suspended in dural sac at T12-L1 so any injury damage motor neurons to LL and parasymps to bowel, bladder, genitalia