Question

1.Know the 31 pairs of spinal nerves and how many in each section

Which areas innervate the cervical and lumbar enlargements?

Answer 1

1. There are 31 pairs of spinal nerves emrges from the spinal cord in the form of ventral roots (motor) and dorsal roots (sensory). These are the mixed nerves which relays both sensory and motor information. They are the integral part of the peripheral nervous system.

Spinal nerves are named according to the vertebrae above which they emerge. The division of the spinal nerves include:

Cervical- 8,

Thoarcic-12,

Lumbar- 5,

Sacral- 5, and

coccyx-1.

The cervical and lumbar enlargemts results from the enlargement of the grey matterwhich controls the limbs. The cervical enlargement extends between c3 to T1, and lumbar enlargement extends between L1 to S2.

The cervical enlargement innervates upper limbs, where as lumbar enlargement innervates lower limbs.