Levator ani muscle

The levator ani is a broad, thin muscle complex forming part of the pelvic diaphragm.

Origin: Medial edge of the shaft of the ilium on the inner surface of the ramus of the pubis and on the entire pubic symphysis.

Insertion: On the hemal process of the seventh caudal vertebra.

Action: Bilateral: to press the tail against the anus and genital parts, unilateral: to bring the tail cranially and laterally. The levatores ani, in combination with the levatores of the tail, cause the sharp angulation between the sixth and seventh caudal vertebrae which is characteristic for defecation: compression of the rectum.

Nerve: Ventral branches of the third sacral and first caudal nerve.