PENILE FASCIAE AND STRUCTURES
In this view, the distal end of the penis is shown intact to demonstrate the glans and the frenulum and the relationship to the foreskin or prepuce. In the sulcus between the corona of the glans and the internal surface of the foreskin are shown the openings of the preputial glands (Tyson glands) that excrete sebaceous material, a main constituent of smegma.
After removing the deep layer of Colles fascia and the overlying bulbospongiosus and ischiocavernosus muscles that cover the penile shaft and crura in Plate 2-3, the true extent of Buck fascia is revealed. In addition to covering the corpus spongiosum and both crura, Buck fascia anchors the bulbous portion of the urethra (corpus spongiosum) and each crus ﬁrmly to the pubis, to the inferior rami of the ischium, and to the urogenital diaphragm. The removal of Colles fascia at its posterior insertion in the urogenital diaphragm exposes the super-ﬁcial transverse perineal muscles and the inferior surface of the urogenital diaphragm. Removing the urogenital diaphragm exposes the deep transverse perineal muscle as shown in Plate 2-5. The crural septum of Colles fascia, which extends between the bulbospongiosus and ischiocavernosus muscles, separates this portion of the perineum into three compartments. The perineal body is the focal point of attachment of the superﬁcial trans- verse perineal muscles from each side and the anterior ﬁbers of the external anal sphincter. Beneath the deep layer of the superﬁcial fascia in the anal triangle, the greater part of the pelvic diaphragm, which includes the levator ani muscle as well as the ischiorectal fossa, is visible. In the lower portion of Plate 2-4, Buck fascia has been removed from the penis, demonstrating the corpus spongiosum, which contains the urethra and also forms the spongiosal glans penis that forms a “cap” over the joined bodies of the corpora cavernosa. To allow for this, the paired corpora terminate distally in a pointed fashion, about 1 to 2 cm from the actual end of the penis. In the treatment of prolonged erections due to ischemic priapism, the blood within the corporal bodies can be joined with that of the spongiosum to relieve this condition by surgically creating a hole between the spongiosal cap and the distal corporal bodies. The intercavernous septum of Buck fascia between the roof of the corpus spongiosum and the corpora cavernosa remains, as previously viewed in cross section in Plate 2-2.
Beneath Buck fascia, each corporal crus of the penis is ﬁrmly ﬁxed to the rami of the pubis and ischium. The cavernous spaces are surrounded by a thick, rigid ﬁbrous capsule (tunica albuginea) consisting of both deep and superﬁcial ﬁbers. The latter course longitudinally and connect both corpora, but the deep ﬁbers run in a circular manner and form a septum between the corpora after they become adjacent. Near the end of the penis, this septum becomes incomplete, allowing commu- nication between the otherwise two distinct corpora cavernosa.