Definition:
corpus cavernosum (KOR-pus KA-ver-NOH-sum)
One of two columns of spongy tissue that runs through the shaft (body) of the penis. The corpus cavernosum forms most of the penis and contains blood vessels that fill with blood to help make an erection.
Enlarge Anatomy of the penis; drawing shows the base, shaft, glans, foreskin, and urethral opening. Also shown are the scrotum, prostate, pubic bone, and lymph nodes. An inset shows a cross section of the inside of the penis, including the blood vessels, dorsal nerve, connective tissue, erectile tissue (corpus cavernosum and corpus spongiosum), and urethra.

Anatomy of the penis. The parts of the penis are the base, shaft, glans, and foreskin. The tissues that make up the penis include the dorsal nerve, blood vessels, connective tissue, and erectile tissue (corpus cavernosum and corpus spongiosum). The urethra passes from the bladder to the tip of the penis.