Neuro 2 - Spinal Cord Function and Dysfunction

Question 1

What are the two enlargements in the spinal cord and what is their significance?

Answer 1

1) Cervical Enlargement - has extra motor neurons that go to the muscles of the upper limbs
2) Lumbosacral englargement

Question 2

What are the little protrusion of pia mater around the spinal cord called?

Answer 2

Denticulate ligaments

Question 3

Which space is present in the spinal meninges but not in the cranial meninges?

Answer 3

Epidural space

Question 4

What are the 3 most important tracts in spinal cord injury?

Answer 4

Lateral corticospinal - fine motor movement
Dorsal columns - touch, pressure, vibration, proprioception
Spinothalamic - pain and temp

Question 5

What are the two stages of lateral corticospinal tract damage?

Answer 5

Spinal shock - loss of reflexes below lesion leading to flaccid paralysis - limbs become floppy

Return of reflexes - hyperreflexia and spasticity

Question 6

Where do the upper motor neurons within the lateral corticospinal decussate?

Answer 6

Pyramidal decussation in the medulla

Question 7

If you have a unilateral lesion of the lateral corticospinal tract in the mid thoracic region, where will the deficit be?

Answer 7

On the same side as the lesion as the fibres decussate at the pyramidal decussation in the medulla

Question 8

Where do the sensory fibres of the dorsal columns decussate?

Answer 8

Sensory decussation in the medulla

Question 9

How are pain neurons arranged different to other sensory and motor neurons?

Answer 9

first order neurons synapse in the dorsal horn and cross over immediately and then the second order neurone travels up

Question 10

What is syringomyelia?

Answer 10

enlargement of the central canal

selectivity affects spinothalamic fibres crossing over at the level of the lesion and not those that have already crossed over