4-Dorsal Column

Question 1

DC-ML transmits what

dorsal column

Answer 1

1. discriminative touch- 2 point and complex
2. stereognosis- 3D characteristics of objects
3. flutter- vibratory
4. general proprioception- position

from body to consciousness

some light touch and visceral nociception

Question 2

testing for 2 point discrimination

Answer 2

caliper tips applied to fingertips 5 mm apart
OR qtips applied to leg 40 mm apart
-less receptors in leg

testing to detect two distinct sensations

Question 3

stereognosis what identify

Answer 3

3D shape, size, contour, edges of solids by tactile sense (eyes closed)

Question 4

weight is a type of ?

Answer 4

proprioception

Question 5

proprioception

definition

Answer 5

position sense about location, orientation, movement of head/trunk/limbs

Question 6

DCML pathway

Answer 6

ascending sensory with 3 neurons

1. neuron I @ DRG
2. neuron II @ NG or NC (medulla)
3. neuron III @ VPL of thalamus

cell bodies

Question 7

what makes up dorsal column

Answer 7

axons fasciulus cuneatus and gracilus

Question 8

gracilis

Answer 8

present at all spinal cord levels but recieve sensory input from ipsilateral lower half of body (via pseudounipolar T7-sacrum)

Question 9

cuneatus

Answer 9

present C1-T6
-sensory input from ipsilateral upper half body (via pseudounipolar C2-T6 bc C1 not have sensory root)

Question 10

tracts become

Answer 10

ascending thicker as ascend as more are added

descneding thin as descend as exit

Question 11

pathway

Answer 11

1. primary neuron @ DRG cell body
2. up FG or FC
3. synapase @ NG or NC in medulla (secondary)
4. decussate via internal arcuate fibers
5. ascending in medial lemniscus
6. synapse @ thalamus (third)
7. post central gyrus
8. sensory association cortex for interpretation

Question 12

post central gyrus

Answer 12

somatosensory

areas 1,2,3

Question 13

precentral gyrus

Answer 13

motor
area 4

Question 14

deficits

Answer 14

ipsilateral = same side as lesion
contralateral= oppo side of lesion

Question 15

arterial supply to DCML

Answer 15

posterior spinal A’s
-if occlude then damage ipsilateral pathways + their nuclei

Question 16

unilateral lesion what happens

Answer 16

loss/impair snesory input from ipsilateral side at and below level of lesion if below decussation
-since fibers are added above lesion not affect

Question 17

occlusion in medulla

Answer 17

occlude posterior spinal damage
-dorsal pathways and their nuclei

Question 18

occlude anterior spinal A

Answer 18

affect medial lemniscus
-loss of proprioception and vibratory sense

Question 19

ML lesion

medial lemniscus

Answer 19

sensory deficits contralateral to side of lesion
-bc above decussation so pathway crossed already

Question 20

rhomberg’s sign

Answer 20

diffuculty maintaining blance with eyes closed and feet together

Question 21

sensory ataxia

Answer 21

sensory incoordination, proprioception not work
-will walk heavy and look down at limbs bc can’t feel what they’re doing

Question 22

cuneocerebellar tract

Answer 22

upper trunk
-nonconscious sensory/proprioception
-heavily myelinated

Question 23

dorsal spinocerebellar tract

Answer 23

trunk and lower limb nonconscious proprioception
-heavilly myelinated

Question 24

rostral spinocerebellar tract

Answer 24

upper limb
-nonconscious propriocep
-heavy myelinated

Question 25

ventral spinocerebellar ttract

Answer 25

lower trunk
-nonconscious proprio
-heavy myelinated

Question 26

anterior cerebral A occlusion

Answer 26

lesion in medial surface of brain
-sensory deficits in contralateral leg and foot

Question 27

middle cerebral A occlusion

Answer 27

lesion in lateral surface
-sensory def in contralat upper limb and face

Question 28

lenticulostriate arteries

Answer 28

deeper branches of middle cerebral A
-supply anterior and post limbs of internal capsule

if occlude then sensory def in contralat side of body

third order neuron of DC @posterior limb

Question 29

posterior cerebral A occlusion

Answer 29

deficit in contralateral side of body

Question 30

basilar A occlusion

Answer 30

supplies caudal pons and medial lemniscus

deficit in contralat side body

Question 31

vertebral A occlusion

Answer 31

supplies rostral medulla and medial lemniscus

deficit contralateral