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 :
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
- 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.