Anatomical relationships of the penis
The erectile components of the penis relate, laterally, to the overlying elastic skin of the penis. Medially, the corpora cavernosa are effectively joined and, in the space immediately above that, relate to the deep dorsal vein and dorsal nerve of the penis. The corpus spongiosum incorporates the urethra. Posteriorly and laterally, it relates to the elastic skin of the penis. The origins of the penis relate to the anterior part of the bony pelvis, in particular, the symphysis pubis, to which it is attached by a suspensory ligament and, laterally, to the rami of the pubis, to which are attached the corpora cavernosa. Underneath the symphysis pubis, there is an arch of bone which is filled by the perimeal membrane. Attached to this is the corpus spongiosum. The urethra passes through this membrane at the point of its membranous segment. Also passing through this membrane, are the blood vessels to the corpora cavernosa and the nerves to the penis and, in particular, its erectile tissues.