part of part of intersects midsagittal plane of has quality has quality develops from develops from ridged perineum mesoderm-derived structure urogenital fold external soft tissue zone raphe of perineum It is the result of a fetal developmental phenomenon whereby the scrotum (the developmental equivalent of the labia in females) and penis close toward the midline and fuse. The resulting ridge of tissue is evident as the perineal raphe perineal raphe The perineal raphe extends from the anus, through the mid-line of the scrotum (scrotal raphe) and upwards through the posterior mid-line aspect of the penis (penile raphe). Wikipedia:Perineal_raphe raphe perinei UBERON:0035106 raphe perinealis FMA:20244