Anatomy of Vulva and Perineum

Vulva and Perineum

The perineum comprises the area of the surface of the trunk between the thighs and the buttocks, extending from the coccyx to the pubis. Anatomists also use the term “perineum” torefer to the shallow compartment that lies deep to this area and inferior to the pelvic diaphragm.

The vulva contains the labia majora, labia minora, mons pubis, clitoris, vestibule, and ducts of glands that open into the vestibule (Fig. 4.9). The labia majora are folds of skin with underlying adipose tissue, fused anteriorly with the mons pubis and posteriorly at the perineum. The skin of the labia majora contains hair follicles as well as seba-ceous and sweat glands. The labia minora are narrow skin folds lying inside the labia majora. The labia minora merge anteriorly with the prepuce and frenulum of the clitoris, and posteriorly with the labia majora and the perineum. The labia minora contain sebaceous and sweat glands, but no hair follicles, and there is no underlying adipose tissue. The clitoris, which is located anterior to the labia minora, is theembryologic homolog of the penis. It consists of two crura (corresponding to the corpora cavernosa in the male) and the glans, which is found superior to the point of fusion of the crura. On the ventral surface of the glans is the frenu-lum, the fused junction of the labia minora. 

The vestibule lies between the labia minora and is bounded anteriorly by the clitoris and posteriorly by the perineum. The urethra and the vagina open into the vestibule in the midline. The ducts of Skene (paraurethral) glands and Bartholinglands also empty into the vestibule. Secretions from theBartholin glands are responsible for sexually stimulated vaginal lubrication.

The muscles of the vulva (superficial transverse per-ineal, bulbocavernosus, and ischiocavernosus) lie superficial to the fascia of the urogenital diaphragm (Fig. 4.10). The vulva rests on the triangular-shaped urogenital diaphragm, which lies in the anterior part of the pelvis between the ischiopubic rami