- Bulbospongiosus muscle
Infobox Muscle
Name = Bulbospongiosus muscle
Latin = musculus bulbospongiosus
GraySubject = 120
GrayPage = 428
Caption = Muscles of the female perineum. (Bulbocavernosus visible at upper right.)
Caption2 = Muscles of male perineum. (Bulbocavernosus visible at upper left.)
Origin = Median raphé
Insertion =
Blood =Perineal artery
Nerve =pudendal nerve
Action = in males, empties theurethra ; in females, clenches thevagina
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DorlandsPre = m_22
DorlandsSuf = 12548543Bulbospongiosus (bulbocavernous in older texts) is one of the superficial
muscle s of theperineum . It has a slightly different origin, insertion and function in males and females. In males, it covers thebulb of the penis . In females, it covers thevestibular bulb .In both sexes, it is innervated by the deep/muscular branch of the
perineal nerve , which is a branch of thepudendal nerve .Action
In males it contributes to
erection ,ejaculation , and the feelings oforgasm . In females it contributes toerection and the feelings of orgasm, and closes thevagina .This muscle serves to empty the canal of the
urethra , after the bladder has expelled its contents; during the greater part of the act ofmicturition its fibers are relaxed, and it only comes into action at the end of the process.The middle fibers are supposed by Krause to assist in the erection of the
corpus cavernosum urethræ , by compressing the erectile tissue of the bulb.The anterior fibers, according to Tyrrel, also contribute to the erection of the penis by compressing the
deep dorsal vein of the penis as they are inserted into, and continuous with, the fascia of the penis.Location
The bulbospongiosus is placed in the middle line of the
perineum , in front of theanus . It consists of two symmetrical parts, united along the median line by a tendinousraphé .It arises from the central tendinous point of the
perineum and from themedian raphé in front.Fibers
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 thecorpus cavernosum urethræ , and join with the fibers of the opposite side, on the upper part of the corpus cavernosum urethræ, in a strongaponeurosis ; the anterior fibers, spread out over the side of the corpus cavernosumpenis , to be inserted partly into that body, anterior to theIschiocavernosus , 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 urethræ.
=AdditionalExternal links
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* - "The Female Perineum: Muscles of the Superficial Perineal Pouch"
* - "Muscles of the male superficial perineal pouch. "
* - "The urinary bladder and the urethra as seen in a frontal section of the female pelvis."
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