Raphe
From Biocrawler, the free encyclopedia.
The raphe is a continuous ridge of tissue which extends from the anus (perineal raphe), through the mid-line of the scrotum (scrotal raphe) and upwards through the posterior mid-line aspect of the penis (penile raphe). It is observed as a noticeable line. 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 raphe.
Other examples of developmental raphae are the buccal raphe which is on the cheek and evidence of the fusion of the maxillary and mandibular processes, the lingual raphe on the tongue, and the palatine raphe on the roof of the mouth (or palate). Incomplete fusion of the palatine raphe results in a congenital defect known as cleft palate. Obvious physical evidence of the lingual raphe includes the frenulum (also called the frenum), or band of mucous membrane that is visible under the tongue attaching it to the floor of the mouth. If this raphe is too tight at birth, movement of the tongue is restricted and the child is said to be "tongue tied".
