FIGURE 2-3 Vulvar structures and subcutaneous layer of the anterior perineal triangle. Note the continuity of Colles and Scarpa fasciae. Inset: Vestibule boundaries and openings onto vestibule. (Reproduced with permission from Corton MM: Anatomy. In Hofman BL, Schorge JO, Bradshaw KD, et al (eds): Williams Gynecology, 3rd ed. New York, McGraw-Hili Education, 2016.) outer surface of each labium. On their inner surface, the lateral portion is covered by this same epithelium up to a demarcating line, termed Hart line. Medial to this line, each labium is covered by squamous epithelium that is nonkeratinized. he labia minora lack hair follicles, eccrine glands, and apocrine glands. However, sebaceous glands are numerous (Wilkinson, 2011).
he clitoris is the principal female erogenous organ. It is located beneath the prepuce, above the frenulum and urethra, and projects downward and inward toward the vaginal opening. The clitoris rarely exceeds 2 cm in length and is composed of a glans, a corpus or body, and two crura (Verkauf, 1992). he glans is usually less than 0.5 cm in diameter, is covered by stratified squamous epithelium, and is richly innervated. he clitoral body contains two corpora cavernosa. Extending from the clitoral body, each corpus cavernosum diverges laterally to form a long, narrow crus. Each crus lies along the inferior surface of its respective ischiopubic ramus and deep to the ischiocavernosus muscle. The clitoral blood supply stems from branches of the internal pudendal artery. Specifically, the deep artery of the clitoris supplies the clitoral body, whereas the dorsal artery of the clitoris supplies the glans and prepuce.
In adult women, the vestibule is an almond-shaped area that is enclosed by Hart line laterally, the external surface of the hymen medially, the clitoral frenulum anteriorly, and the fourchette posteriorly (see Fig. 2-3). The vestibule is usually perforated by six openings: the urethra, the vagina, two Bartholin gland ducts, and two ducts of the largest paraurethral glands-the
Skene glands. he posterior portion of the vestibule between the fourchette and the vaginal opening is called the fossa navic ularis. It is usually observed only in nulliparas.
The bilateral Bartholin glands, also termed greater vestibular glands, measure 0.5 to 1 cm in diameter. On their respective side, each lies inferior to the vestibular bulb and deep to the inferior end of the bulbospongiosus muscle (former bulbocavernosus muscle). A duct extends medially from each gland, measures 1.5 to 2 cm long, and opens distal to the hymeneal ring-one at 5 and the other at 7 o'clock on the vestibule. Following trauma or infection, either duct may swell and obstruct to form a cyst or, if infected, an abscess. In contrast, the minor vestibular glands are shallow glands lined by simple mucinsecreting epithelium and open along Hart line.
he paraurethral glands are a collective arborization of glands whose numerous small ducts open predominantly along the entire inferior aspect of the urethra. he two largest are called Skene glands, and their ducts typically lie distally and near the urethral meatus. Clinically, inlammation and duct obstruction of any of the paraurethral glands can lead to urethral diverticulum formation. The urethral opening or meatus is in the midline of the vestibule, 1 to 1.5 cm below the pubic arch, and a short distance above the vaginal opening.