Figure 4-7
Section through the body of the penis.

The external male genitalia consist primarily of the penis, although you could include the scrotum and testes in this category.

The penis is composed of three columns of erectile tissue. The outer two columns, the corpora cavernosa are attached to the inferior rami of the pubic bones. The single center column, the corpus spongiosum, houses the urethra. During erection, all three columns become engorged with blood erecting the penis for vaginal penetration (Figure 4-7).