ABSTRACT
Inferior to the corpora cavernosa lies the corpus spongiosum (Fig. 3), which contains the urethra and extends distally to form the majority of the glans penis (11). The penile corporeal tissue is surrounded by another dense fascial sheath (Buck’s fascia) (Fig. 2), which anchors the penis to the symphysis pubis and compresses the circumflex veins during the erectile responses, thereby further limiting venous drainage (10). Histologically, the tissue of the corpora cavernosa consists of bundles of smooth-muscle fibers intertwined in a collagenous extracellular matrix. Interspersed within this parenchyma is a complex network of endothelial cell-lined sinuses (lacunae), helicine arteries, and nerve terminals (12).
