spinal cord

Question 1

components of spinal cord

Answer 1

central grey matter-neuronal cell bodies/synapes peripheral white matter-ascending sensory fiber pathways and descending motor fiber pathways

Question 2

3 sensory systems entering the spinal cord

Answer 2

pain/temperature, proprioception, light touch

Question 3

pathway for pain and temperature

Answer 3

crosses to opposite side of cord immediately, to opposite thalamus, then cerebral cortex

Question 4

effects of spinothalamic tract lesion

Answer 4

loss of pain temperature on contralateral side below the level of the lesion

Question 5

stereognosis

Answer 5

the mental perception of 3D, to perceive the form of solid objects by touch

Question 6

pathway for proprioception/stereognosis/vibration

Answer 6

remain on same side of cord, cross over at junction of spinal cord and brain stem, synaptic areas before crossing are nucleus cuneatus and nucleus gracilis

Question 7

nucleus gracilis

Answer 7

conveys proprioception info from lower part of the body

Question 8

nucleus cuneatus

Answer 8

conveys proprioception from upper body

Question 9

posterior columns

Answer 9

include spinal cord pathways fasciculus gracilis and fasciculus cuneatus

Question 10

effect of lesion of posterior columns

Answer 10

decrease in conscious proprioception/stereognosis and vibration on the same side below the level of the lesion

Question 11

light touch pathway

Answer 11

parts cross and parts uncrossed, so usually spared with unilateral lesion

Question 12

spinocerebellar pathway

Answer 12

responsible for unconscious proprioception, to walk and perform complex acts , stays ipsilateral to cerebellum so cerebellar lesions produce same side malfunction- enter cerebellum via superior and inferior peduncles

Question 13

3 connection between cerebellum/brain stem

Answer 13

superior(midbrain), middle(pons), and inferior cerebellar (medulla) peduncles

Question 14

corticospinal (motor) pathway

Answer 14

motor area of cerebral cortex thru brainstem, crosses over at level of medial lemniscus (junction of brain stem/spinal cord)

Question 15

upper motor neuron defect

Answer 15

spastic paralysis, no sig muscle atrophy, hyperreflexia, +babinski possible

Question 16

lower motor neuron deficit

Answer 16

flaccid paralysis, significant atrophy, fasciculations and fibrillations, hyporeflexia, negative Babinski

Question 17

fasciculations and fibrillations

Answer 17

muscle twitches

Question 18

difference between UMN and LMN lesions

Answer 18

UMN lesions involve anterior horns of gray matter

LMN lesions involve corticospinal tracts

Question 19

pyramidal

Answer 19

referring to corticospinal system, other motor pathways outside this system are extrapyramidal

Question 20

spinal cord blood supply

Answer 20

anterior spinal artery for anterior 2/3s of cord
2 posterior spinal arteries from posterior inferior cerebellar arteries or vertebral arteries and supply posterior column (conscious proprioception/stereognosis)

Question 21

Brown Sequard syndrome

Answer 21

hemisection of cervical cord, causes ipsilateral paralysis/loss of stereognosis, contralateral loss of pain/temperature