Henry Gray (18251861). Anatomy of the Human Body. 1918.
penis, extending farther on their upper than on their lower surfaces. At the summit of the glans is the slit-like vertical external urethral orifice. The circumference of the base of the glans forms a rounded projecting border, the corona glandis, overhanging a deep retroglandular sulcus, behind which is the neck of the penis.
For descriptive purposes it is convenient to divide the penis into three regions: the root, the body, and the extremity.
The root (radix penis) of the penis is triradiate in form, consisting of the diverging crura, one on either side, and the median urethral bulb. Each crus is covered by the Ischiocavernosus, while the bulb is surrounded by the Bulbocavernosus. The root of the penis lies in the perineum between the inferior fascia of the urogenital diaphragm and the fascia of Colles. In addition to being attached to the fasciæ and the pubic rami, it is bound to the front of the symphysis pubis by the fundiform and suspensory ligaments. The fundiform ligament springs from the front of the sheath of the Rectus abdominis and the linea alba; it splits into two fasciculi which encircle the root of the penis. The upper fibers of the suspensory ligament pass downward from the lower end of the linea alba, and the lower fibers from the symphysis pubis; together they form a strong fibrous band, which extends to the upper surface of the root, where it blends with the fascial sheath of the organ.
The body (corpus penis) extends from the root to the ends of the corpora cavernosa penis, and in it these corpora cavernosa are intimately bound to one another. A shallow groove which marks their junction on the upper surface lodges the deep dorsal vein of the penis, while a deeper and wider groove between them on the under surface contains the corpus cavernosum urethræ. The body is ensheathed by fascia, which is continuous above with the fascia of Scarpa, and below with the dartos tunic of the scrotum and the fascia of Colles.