perineum /per′inē″əm/ [Gk, perineos] , the part of the body situated dorsal to the pubic arch and the arcuate ligaments, ventral to the tip of the coccyx, and lateral to the inferior rami of the pubis and the ischium and the sacrotuberous ligaments. The perineum supports and surrounds the distal parts of the urogenital and GI tracts of the body. In the female the central fibrous perineal body is larger than in the male; the bulbospongiosus, which is a sphincter around the orifice of the vagina and a cover over the clitoris, does not exist in the male perineum. In men and women the muscles are innervated by the perineal branch of the pudendal nerve. −perineal, adj.