Corpus: Corpus spongiosum penis
1. Definition
2. Anatomy
The corpus spongiosum penis is located on the underside of the penis and surrounds the entire cavernous part of the urethra in a cuff-like shape. At the base of the penis, it forms a bulbous structure known as the bulb of the penis.
Unlike the corpus cavernosum penis, the corpus spongiosum penis has only a weak tunica albuginea. It is classified as a venous erectile tissue, meaning blood flows through it even when the penis is flaccid. It consists of a spongy, cavernous venous plexus surrounded by connective tissue, with smooth muscle cells embedded within.
The swelling of the corpus spongiosum occurs due to the restriction of venous blood outflow, though it contributes only weakly to the erection. Its primary function is to cushion the urethra during an erection, ensuring the passage of semen.