Spinal cord

Question 1

Alpha motor neurons innervate?

Answer 1

extrafusal muscle

Question 2

Gama motor neurons innervate ?

Answer 2

intrafusal muscle ( reflex , unconscious )

Question 3

What changes are seen with lesions along the long tracts ?

Answer 3

deficits at and below lesion ( contra or ipsilateral)

Question 4

Where are the changes seen with grey matter lesions?

Answer 4

ipsilateral at the level of the lesion

Question 5

Type 1 a muscle fibers are …

Answer 5

muscle spindle reflex fibers

Question 6

Where does decussation occur for the corticospinal tract ?

Answer 6

Caudal medulla

Question 7

What passes through the internal capsule?

Answer 7

corticospinal tract-P
somatosensory -P
optic & auditory -P
corticobulbar -G
Frontopontine-A

Question 8

UMN lesions results in what type of weakness?

Answer 8

Spastic weakness

Question 9

LMN lesions result in what type of weakness?

Answer 9

Flaccid weakness

Question 10

Why is spasticity seen with UMN lesions?

Answer 10

because UMN have increased stretch reflex innervation –> continuous contraction

Question 11

What is the grading for reflexes ?

Answer 11

0- Absence 
1- Reduced or weak 
2- normal reflex 
3- hyperreflxia
4- very brisk

Question 12

Where does the dorsal column/ medial lemniscus pathway decussate?

Answer 12

Caudal medulla

Question 13

Fasciculus gracilis

Answer 13

medial
lower limb & trunk
entire cord

Question 14

Fasciculus cuneatus

Answer 14

lateral

upper limb & trunk above T5

Question 15

Where does 2nd neuron of the dorsal column/ medial lemniscus synapse

Answer 15

N. cuneatus
N. gracilis
in the medulla

Question 16

Where is the final synapse for the dorsal column/ medial leminiscus pathway?

Answer 16

VPL

ventroposterolateral nucleus

Question 17

Where does the spinothalamic decussate ?

Answer 17

At the level of the spinal lesion

Question 18

What are the fibers of pain and temperature ?

Answer 18

Alpha-delta

c fibers

Question 19

Spinothalamic tracts decussate in ?

Answer 19

Ventral white commissure

Question 20

Cuneocerebellar deficits cause?

Answer 20

upper limb ataxia

Question 21

Dorsal spinocerebellar deficit cause

Answer 21

lower limb ataxia

Question 22

Lower spinal cord blood supply comes from

Answer 22

Adamkiwewicz

intercostal and lumbar arteries

Question 23

Upper spinal cord blood supply comes from ?

Answer 23

ASA

PSA

Question 24

Poliomyelitis

Answer 24

deficit of LMN in the ventral horns

Question 25

ALS

Answer 25

deficit in corticospinal tract and ventral horns--> UMN & LMN

Question 26

Tabes Dorsalis

Answer 26

seen with syphilis | deficit of dorsal columns and dorsal roots

Question 27

ASA blood supply damage

Answer 27

bilateral CST bilateral STT bilateral flaccid (LMN) ventral horn

Question 28

Subacute combined degeneration

Answer 28

deficit of B12 --> dorsal column, corticospinal, spinocerebellar deficits

Question 29

Syringomyelia

Answer 29

bilateral loss of pain & temperature --> cape lesion

Question 30

Brown - Squared syndrome

Answer 30

hemisection deficit ( DC, CST, STT, LMN)