The Grey Matter of the spine

Question 1

The grey matter is divided into which 4 columns?

Answer 1

the dorsal horn
the intermediate column
the lateral horn
and the ventral horn:

Question 2

What neurons does the dorsal horn contain?

Answer 2

The dorsal horn (also known as the posterior horn) contains neurons that receive somatosensory information from the body, which is then transmitted via the ascending pathways, to the brain.

Question 3

What neurons does the lateral and intermediate horn contain?

Answer 3

The intermediate column and lateral horn contain neurons that innervate visceral and pelvic organs.

Question 4

What neurons does the ventral horn contain?

Answer 4

The ventral horn (also known as the anterior horn) largely contains motor neurons that exit the spinal cord to innervate skeletal muscle.

Question 5

List the prominent nuclei groups in the spinal cord

Answer 5

• Marginal zone (MZ, posterior marginalis)
• Substantia gelatinosa (SG)
• Nucleus proprius (NP)
• Dorsal nucleus of Clarke (DNC)
• Interomediolateral nucleus (IMN)
• Lateral motor neurons and medial motor neurons (MNs)

Question 6

Location and function of nuclei in the Marginal zone (MZ, posterior marginalis)

Answer 6

Marginal zone (MZ, posterior marginalis) – located at the tip of the dorsal horn, and is important for relaying pain and temperature sensation to the brain.

Question 7

Location and function of the nuclei in the Substantia gelatinosa (SG)

Answer 7

Substantia gelatinosa (SG) – located at the top of the dorsal horn, the SG is important for relaying pain, temperature and light touch sensation to the brain.

Question 8

Location and function of the nuclei in the Nucleus proprius (NP)

Answer 8

Nucleus proprius (NP) – located in the ‘neck’ of the dorsal horn, the NP relays mechanical and temperature sensation to the brain.

Question 9

Location and function of the nuclei in the Dorsal nucleus of Clarke (DNC)

Answer 9

Dorsal nucleus of Clarke (DNC) – the most dorso-medial nuclei, the DNC relays unconscious proprioceptive information to the brain. Only found in spinal segments C8 to L3.

Question 10

Location and function of nuclei in the Interomediolateral nucleus (IMN)

Answer 10

Interomediolateral nucleus (IMN) – located in the intermediate column and lateral horn, the IMN relays sensory information from viscera to the brain, and autonomic signals from the brain to the visceral organs.

Question 11

Location and function of nuclei in the Lateral motor neurons and medial motor neurons (MNs)

Answer 11

Lateral motor neurons and medial motor neurons (MNs) – located in the ventral horn. Composed of motor neurons that innervate visceral and skeletal muscles.