The cervical enlargement corresponds to which limbs?

The cervical enlargement corresponds to which limbs?

• A. Upper limbs
• B. Lower limbs
• C. Both upper and lower limbs
• D. Face muscles

Answer: (A)

The main idea is that enlargements in the spinal cord reflect where the neurons needed to control the limbs are concentrated. The cervical enlargement contains a larger amount of gray matter because it houses the motor neurons that innervate the upper limb muscles through the brachial plexus. This is why the cervical region is associated with the upper limbs. By contrast, the lower limbs are served by the lumbar (and sacral) enlargement, and muscles of the face are controlled by cranial nerves in the brainstem, not by spinal cord enlargements. So the cervical enlargement corresponds to the upper limbs.

The main idea is that enlargements in the spinal cord reflect where the neurons needed to control the limbs are concentrated. The cervical enlargement contains a larger amount of gray matter because it houses the motor neurons that innervate the upper limb muscles through the brachial plexus. This is why the cervical region is associated with the upper limbs. By contrast, the lower limbs are served by the lumbar (and sacral) enlargement, and muscles of the face are controlled by cranial nerves in the brainstem, not by spinal cord enlargements. So the cervical enlargement corresponds to the upper limbs.