Spinal Cord and Basic Reflexes

Question 1

What are funiculi?

Answer 1

Columns of white matter

Question 2

Describe sensory input and motor output in the spinal cord.

Answer 2

. Afferent (sensory) neurones feed into dorsal horn

. Efferent (motor) neurones stem from ventral horn

Question 3

How many vertebra are present in each spinal segment?

Answer 3

. Cervical- 7
. Thoracic- 12
. Lumbar- 5
. Sacral- 5
. Coccygeal- 3 to 5 (fused)

Question 4

Give one difference between the newborn and adult spine.

Answer 4

Adult spine has the cauda equina (where nerve roots split to pass through holes leading to the pelvis to innervate the lower limbs)

Question 5

Compare epidural and a spinal/subarachnoid drugs.

Answer 5

. Epidural drugs only act locally
. Spinal/subarachnoid drugs diffuse throughout the CNS (NB: cerebrospinal fluid continues into brain, so any drug administered this way can reach brain)

Question 6

What is a motor unit?

Answer 6

Group of muscle fibres innervated by a single spinal motor neurone

Question 7

What is Babinski’s reflex? What is the normal response in a healthy adult?

Answer 7

. Stroke bottom of foot with blunt object

. Normal adults show flexor response, where toes curl down towards plantar surface