GENERAL HISTOLOGY

Detailed explanation-1: -The cervical region of the cord gives rise to eight cervical nerves (C1-C8), the thoracic to twelve thoracic nerves (T1-T12), the lumbar to five lumbar nerves (L1-L5), the sacral to five sacral nerves (S1-S5), and the coccygeal to one coccygeal nerve.

Detailed explanation-2: -The cervical enlargement is the site of the cell bodies of the motor neurons that innervate the upper limbs, as well as the site where the sensory nerves from the upper limbs synapse.

Detailed explanation-3: -The cervical enlargement is the more pronounced, and corresponds with the attachments of the large nerves which supply the upper limbs. It extends from about the third cervical to the second thoracic vertebra, its maximum circumference (about 38 mm.)

Detailed explanation-4: -The cervical and lumbar regions of the spinal cord show a larger diameter compared to the rest of the regions. The cervical enlargement and lumbar enlargement represent an increased amount of neurons in the gray matter and axons in the white matter that serve the upper limbs and lower limbs, respectively.