The Transversus perinei superficialis (Transversus perinei; Superficial transverse perineal muscle) is a narrow muscular slip, which passes more or less transversely across the perineal space anterior to the anus

Anus

The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...

.

Origin and insertion

It arises by tendinous fibers from the inner and forepart of the tuberosity of the ischium, and, running medially, is inserted into the central tendinous point of the perineum (perineal body), joining in this situation with the muscle of the opposite side, with the Sphincter ani externus muscle

Sphincter ani externus muscle

The Sphincter ani externus is a flat plane of muscular fibers, elliptical in shape and intimately adherent to the integument surrounding the margin of the anus.-Anatomy:...

 behind, and with the Bulbospongiosus muscle

Bulbospongiosus muscle

Bulbospongiosus 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 front.

In some cases, the fibers of the deeper layer of the Sphincter ani externus decussate in front of the anus and are continued into this muscle. Occasionally it gives off fibers, which join with the Bulbocavernosus of the same side.

Variations are numerous. It may be absent or double, or insert into Bulbocavernosus or External sphincter.

External links

- "The Female Perineum: Muscles of the Superficial Perineal Pouch"