3 - Tracts of Spinal Cord (13)

Question 1

the spinal cord extends from _ to _

Answer 1

foramen magnum to L1

Question 2

What is the major descending pathway called?

Answer 2

corticospinal (aka pyramidal tract)

Question 3

lesions prior to decussation ascending tracts produce _ sensory defects

Answer 3

ipsilateral

Question 4

lesions after decussation of ascending tracts produce _ sensory defects

Answer 4

contralateral

Question 5

lesions prior to decussation of descending tracts produce _ motor defects

Answer 5

contralateral

Question 6

lesions after decussation of descending tracts produce _ motor defects

Answer 6

ipsilateral

Question 7

1st order neuron of ascending pathway is in _

Answer 7

cell body of posterior root ganglion of spinal cord

Question 8

cell body of 2nd order neuron of ascending pathway is in _

Answer 8

gray matter of spinal cord (decussates here)

Question 9

cell body of 3rd order neuron in ascending pathway is in_

Answer 9

thalamus

Question 10

in posterior column:
fasciculus gracilis: _
fasciculus cuneatus: _

Answer 10

up to and including T6

above T6

Question 11

posterior column neurons decussate at _

Answer 11

caudal medulla

Question 12

posterior column is for what sensations?

Answer 12

fine touch, pressure, vibration

Question 13

anterolateral system carries what sensations?

Answer 13

anterior - crude touch and pressure

lateral - pain and temp

Question 14

anterolateral system uses which tract? and decussate where?

Answer 14

spinothalamic; immediately

Question 15

spinotectal tract carries which sensory information?

Answer 15

reflexive and head movements towards tactile stimuli

Question 16

spinotectal tract synapses in _ of midbrain

Answer 16

superior colliculus

Question 17

spinotectal tract decussates where?

Answer 17

immediately

Question 18

posterior spinocerebellar tract relays info about _

Answer 18

proprioceptive information from lower limbs

Question 19

cuneocerebellar tract relays info about _

Answer 19

proprioceptive information from upper limbs

Question 20

anterior spinal cerebellar tract relays information about _

Answer 20

integrates proprioceptive and descending motor with lower limbs

Question 21

rostral spinocerebellar tract relays information about _

Answer 21

integrates proprioceptive and descending motor info with upper limbs

Question 22

most descending (including corticospinal) pathways decussate and _

Answer 22

medulla (85% at pyramids)

Question 23

main descending pathway:

Answer 23

corticospinal tract (pyramidal tract)

Question 24

2/3 fibers originate in _, 1/3 originate in _

Answer 24

precentral, postcentral

Question 25

2/3 fibers originate in _, 1/3 originate in _

Answer 25

precentral, postcentral

Question 26

vestibulospinal tract does:

Answer 26

stablization of head during body movements

Question 27

reticulospinal tract does:

Answer 27

coordination of primitive motor movements (breathing)

Question 28

rubrospinal tract does:

Answer 28

motor control of upper limbs (comatose posturing)

Question 29

tectospinal tract does:

Answer 29

orientaton of head and neck during eye movements

Question 30

lateral corticospinal tract does:

Answer 30

movement of limbs

Question 31

anterior corticospinal tract does:

Answer 31

postural stabilization of trunk and core

Question 32

lesion of midbrain-red nucleus, _ posture

Answer 32

decerebrate

Question 33

decerebrate posture: _

Answer 33

extension of all limbs

Question 34

lesion rostral to red nucleus, _ posture

Answer 34

decorticate

Question 35

decorticate posture: _

Answer 35

flexion of upper limbs