The perineum is a region at the inferior end of the trunk which is situated between the thighs and the lower part of the buttocks. It is a diamond-shaped space at the angles of which are found the inferior pubic (arcuate) ligament above, the tip of the coccyx below, and the ischial tuberosities at each side. The pubic arch and the sacrotuberous ligaments form its sides, but the latter are hidden by the gluteus maximus muscles. If a line is drawn from the anterior part of one ischial tuberosity in front of the anus to the anterior part of the other tuberosity, this diamond-shaped area becomes conveniently divided into an anterior urogenital triangle and a posterior anal triangle (Fig. 573). The anal triangles are about the same in both sexes, but the urogenital triangles differ. On the surface the urogenital triangle is bounded by the mons veneris in front, by the gluteal region (buttocks) behind and by the femoral region (thigh) at each side.
KeywordsPudendal Nerve External Genitalia Ischial Tuberosity Superficial Fascia Ischiorectal Fossa
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