Corpus spongiosum penis
|Corpus spongiosum penis|
Lower Parts of the Genital and Urinary Tracts in the Male
Dissection of the Penis
|Latin||Corpus spongiosum penis
(plural: Corpora spongiosa penium),
(corpus cavernosum urethrae)
The corpus spongiosum is the mass of spongy tissue surrounding the male urethra within the penis. Although called corpus cavernosum in older texts (reference title and dates needed) , this is not correct.
The urethra enters the bulb nearer to the superior than to the inferior surface. On the latter there is a median sulcus (groove), from which a thin fibrous septum (wall) projects into the substance of the bulb and divides it imperfectly into two lateral lobes or hemispheres.
The portion of the corpus spongiosum in front of the bulb lies in a groove on the under surface of the conjoined corpora cavernosa penis. It is cylindrical in form and tapers slightly from behind forward. Its anterior end is expanded in the form of an obtuse cone, flattened from above downward. This expansion, termed the glans penis, is moulded on the rounded ends of the corpora cavernosa penis, extending farther on their upper than on their lower surfaces.
The circumference of the base of the glans forms a rounded projecting border, the corona glandis, overhanging a deep retroglandular sulcus (Meiring's sulcus), behind which is the neck of the penis.
The function of the corpus spongiosum in erection is to prevent the urethra from pinching closed, thereby maintaining the urethra as a viable channel for ejaculation. To do this, the corpus spongiosum remains pliable during erection while the corpora cavernosum penis becomes engorged with blood.
Diagram of the arteries of the penis.
- Anatomy photo:44:06-0204 at the SUNY Downstate Medical Center - "The Male Pelvis: The Urethra"