Quick Facts
The corpus spongiosum penis is the column of erectile tissue surrounding the urethra in the penis; its distal expansion forms the glans penis (Dorland, 2011).
Structure and/or Key Feature(s)
The corpus spongiosum penis is an erectile tissue that surrounds the spongy part of the male urethra within the penis. The proximal and distal parts of the corpus spongiosum are enlarged to form the bulb and glans of the penis.
Cavernous spaces in the corpus spongiosum are dilatable spaces that fill with blood during erection. However, the corpus spongiosum never becomes as firmly erect as the corpora cavernosa. While it does become engorged with blood, it does not become rigid, which is essential; since it would pinch shut the urethra and prevent ejaculation.
The tunica albuginea is thinner than that of the corpora cavernosa and the cavernous sinuses are smaller in the corpus spongiosum. For these reasons, it's incapable of complete erection.
Anatomical Relations
The corpus spongiosum is located on the ventral surface of the penile body, whereas the corpus cavernosum is located on the dorsal surface. The spongy (penile) urethra travels throughout the length of the corpus spongiosum.
Function
Cavernous spaces in the corpus spongiosum fill with blood during erection but not sufficiently to prevent the urethra from closing to allow for ejaculation.
List of Clinical Correlates
—Urethral catheterization
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
