Before proceeding to a discussion of the anatomy of the perineum, it is interesting to note that the pure anatomist has no counterpart for some of the terms used by the surgeon. Denonvilliers' fascia, the rectourethralis muscle, Buck's fascia and Colles' fascia are surgical terms used to designate conveniently certain anatomic landmarks which to the anatomist are not definite structures. The lack of liaison between the dissecting room and the operating amphitheater is responsible for much of our inaccurate knowledge and bizarre perineal surgery.
Probably because of the hardened fasciae in embalmed bodies, there is a tendency for the dissector to consider the urogenital diaphragm as the keystone of the perineum, the other structures being formed secondarily, and to discredit all theories that do not presuppose the presence of a primary rigid double walled triangular membrane perforated by the urethra. This is largely an assumption which the embryologic facts as