Bulbospongiosus muscle

Bulbospongiosus muscle
Muscles of male perineum. (Bulbocavernosus visible at upper left.)
Muscles of the female perineum. (Bulbocavernosus visible at upper right.)
Details
Origin	Median raphé
Artery	Perineal artery
Nerve	pudendal nerve
Actions	in males, empties the urethra; in females, clenches the vagina
Identifiers
Latin	musculus bulbospongiosus
Dorlands /Elsevier	m_22/12548543
TA	A09.5.02.005
FMA	19729
Anatomical terms of muscle []

Bulbospongiosus (bulbocavernosus in older texts) is one of the superficial muscles of the perineum. It has a slightly different origin, insertion and function in males and females. In males, it covers the bulb of the penis. In females, it covers the vestibular bulb.

In both sexes, it is innervated by the deep/muscular branch of the perineal nerve, which is a branch of the pudendal nerve.

The bulbospongiosus is located in the middle line of the perineum, in front of the anus. It consists of two symmetrical parts, united along the median line by a tendinous raphé.

It arises from the central tendinous point of the perineum and from the median raphé in front.

Its fibers diverge like the barbs of a quill-pen; the most posterior form a thin layer, which is lost on the inferior fascia of the urogenital diaphragm; the middle fibers encircle the bulb and adjacent parts, of the corpus cavernosum urethra, and join with the fibers of the opposite side, on the upper part of the corpus cavernosum urethra, in a strong aponeurosis; the anterior fibers, spread out over the side of the corpus cavernosum penis, to be inserted partly into that body, anterior to the Ischiocavernosus, occasionally extending to the pubis, and partly ending in a tendinous expansion which covers the dorsal vessels of the penis.

The latter fibers are best seen by dividing the muscle longitudinally, and reflecting it from the surface of the corpus cavernosum urethra.

In males it contributes to erection, the contractions of orgasm and ejaculation. In females it contributes to clitoral erection and the contractions of orgasm, and closes the vagina.