Spinal Cord

Question 1

How many spinal nerves are there and how are they split?

Answer 1

31 spinal nerves:

8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal

Question 2

Describe a basic cross section of spinal cord

Answer 2

White matter is on outside, grey matter is on inside.

Ventral horn is larger than dorsal horn and is typically displayed bellow, located just outside the main section is the dorsal root ganglion

There is also a ventral root however no ganglion

Question 3

What is a dermatome

Answer 3

The area of skin innervated by a single nerve

Question 4

What is herpes zoster

Answer 4

A virus that may remain dormant in dorsal root ganglion, travels down the sensory axons and causes severe blistering of the dermatome

Question 5

How does the size of motor neurone cell bodies compare with sensory neurone cell bodies

Answer 5

Motor neurones have larger cell bodies

Question 6

What is the spinothalamic tract and what does it control

Answer 6

Sensory pathway, crosses over in spinal cord
Conveys pain, temperature and course touch

A delta and C afferents

Question 7

What is the dorsal column pathway what does it control

Answer 7

Sensory ascending pathway, crosses over in brain after dorsal column nuclei in medulla

Conveys light touch, proprioception and discriminative touch

Aalpha and Abeta afferents

Question 8

What is the corticospinal tract

Answer 8

Motor pathway, decussates at the lower medulla