his supericial pouch contains several important structures, which include the Bartholin glands, vestibular bulbs, clitoral body and crura, branches of the pudendal vessels and nerve, and the ischiocavernosus, bulbospongiosus, and supericial transverse perineal muscles. Of these muscles, the ischiocavernosus muscles each attach on their respective side to the medial aspect of the ischial tuberosity inferiorly and the ischiopubic ramus laterally. Anteriorly, each attaches to a clitoral crus and may help maintain clitoral erection by compressing the crus to obstruct venous drainage. he bilateral bulbospongiosus muscles overlie the vestibular bulbs and
Crus of clitoriS
Cut edge of ischiocavernous m.
Levator ani m.
�Gluteus maximus m.
FIGURE 2-5 Superficial space of the anterior perineal triangle and posterior perineal triangle. Structures on the left side of the image can be seen after removal of Colles fascia. Those on the right side are noted after removal of the superficial muscles of the anterior triangle. (Modified with permission from Corton MM: Anatomy. In Hoffman BL, Schorge JO, Bradshaw KD, et al (eds): Williams Gynecology, 3rd ed. New York, McGraw-Hili Education, 2016.)
Bartholin glands. They attach to the body of the clitoris anteriorly and the perineal body posteriorly. The muscles constrict the vaginal lumen and aid release of secretions from the Bartholin glands. They also may contribute to clitoral erection by compressing the deep dorsal vein of the clitoris. The bulbospongiosus and ischiocavernosus muscles also pull the clitoris downward. Last, the superficial transverse perineal muscles are narrow strips that attach to the ischial tuberosities laterally and the perineal body medially. They may be attenuated or even absent, but when present, they contribute to the perineal body (Corton, 2016).
The vestibular bulbs are almond-shaped aggregations of veins that lie beneath the bulbospongiosus muscle on either side of the vestibule. They measure 3 to 4 cm long, 1 to 2 cm wide, and 0.5 to 1 cm thick. The bulbs terminate inferiorly at approximately the middle of the vaginal opening and extend upward toward the clitoris. Their anterior extensions merge in the midline, below the clitoral body. During childbirth, veins in the vestibular bulbs may be lacerated or even rupture to create a vulvar hematoma enclosed within the supericial space of the anterior triangle (Fig. 41-11, p. 765).
Deep Space of the Anterior Triangle his space lies deep to the perineal membrane and extends up into the pelvis (Mirilas, 2004). In contrast to the supericial perineal space, the deep space is continuous superiorly with the pelvic cavity (Corton, 2005). It contains portions of urethra and vagina, certain portions of internal pudendal artery branches, and muscles of the striated urogenital sphincter complex (Fig. 2-6).