: corpora cavernosa) is one of a pair of sponge-like regions of erectile tissue, which contain most of the blood in the penis of several animals during an erection.

The corpora cavernosa are two expandable erectile tissues along the length of the penis, which fill with blood during penile erection.

These formations are made of a sponge-like tissue containing trabeculae, irregular blood-filled spaces lined by endothelium and separated by septum of the penis.

In some circumstances, release of nitric oxide precedes relaxation of muscles in the corpora cavernosa and corpus spongiosum, in a process similar to female arousal.

Blood can leave the erectile tissue only through a drainage system of veins around the outside wall of the corpus cavernosum.