Nerve supply of skin of buttock:
Cutaneous innervation of the skin of the buttock is derived from anterior and posterior rami of spinal nerves. To explain this nerve supply, the buttock is divided into four quadrants as explained below:
- Upper medial quadrant: It is supplied by the posterior rami of the upper three lumbar nerves (L1, L2, L3) and upper three sacral nerves (S1, S2, S3)
- Upper lateral quadrant: It is supplied by the lateral branches of iliohypogastric nerve (L1) and twelfth thoracic nerve (T12)
- Lower lateral quadrant: It is supplied by branches from the lateral cutaneous nerve of the thigh (L2, L3)
- Lower medial quadrant: It is supplied by branches from the posterior cutaneous nerve of thigh (S1, S2, S3).
The skin over the coccyx in the floor of the cleft between the buttocks is supplied by small branches that come from the lower sacral and coccygeal nerves.
Lymph drainage of the skin of buttock:
The lymph vessels from the skin of buttock drain into the lateral group of superficial inguinal lymph nodes.