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.