[TA] origin, ramus of ischium; insertion, with its fellow in the perineal body; action, with superficial transverse perineal muscle in forming the transverse element of cross-member (the sagittal element being formed by bulbospongiosus and external anal sphincter muscles) that provides support of the perineum and the pelvic diaphragm above it during increased abdominopelvic pressure; in males, it adds support to the bulb of the penis; nerve supply, pudendal (dorsal nerve of penis/clitoris). SYN: musculus transversus perinei profundus [TA], deep transverse muscle of perineum.