Corpus: Pelvic floor muscles

The term pelvic floor muscles refers to the skeletal muscles in the area of the pelvic floor or small pelvis.

The pelvic floor muscles can be subdivided as follows:

Diaphragma pelvis[Bearbeiten]

The pelvic floor in the narrower sense (diaphragma pelvis) is formed by the following muscles:

• Musculus levator ani
  • pubococcygeus muscle
    • pubovaginalis muscle (in women)
  • puborectalis muscle
  • iliococcygeus muscle
• Musculus coccygeus
• Musculus sphincter ani externus

The muscles that originate from the back of the pubic bone converge dorsally, forming a "V" that is open to the front. The levator hiatus lies between them. The levator legs can be felt through the vagina.

Urogenital diaphragm[Bearbeiten]

The urogenital diaphragm, which is part of the pelvic floor, contains the following muscles:

• Musculus transversus perinei superficialis
• Musculus transversus perinei profundus

Other perineal musculature[Bearbeiten]

The following muscles belong to the other perineal musculature:

• Musculus bulbospongiosus
• Musculus ischiocavernosus
• Musculus sphincter urethrae externus
• Musculus sphincter urethrovaginalis (in women)

Note: The sphincter ani internus muscle is also part of the pelvic floor muscles in the broadest sense. However, it consists of involuntarily innervated smooth muscle and is therefore discussed separately.

The pelvic floor muscles are mainly innervated by the pudendal nerve, which originates from the sacral plexus or pudendal plexus.

The pelvic floor muscles ensure the muscular closure of the pelvis. Together with the diaphragm and the abdominal muscles, they surround the abdominal contents. In the event of an increase in pressure in the abdominal cavity, it elastically absorbs the pressure of the pelvic organs. It thus secures the position of the abdominal and pelvic organs and supports the closure of the anus and urethra.

Dilatation or hypotonia of the pelvic floor muscles leads to ptosis of the internal genital organs in women. This phenomenon is observed particularly after childbirth.

Weakness of the pelvic floor muscles can lead to incontinence. If the problem is purely functional and anatomical lesions can be ruled out, the treatment of choice is physiotherapy-led pelvic floor strengthening.

If the pelvic floor muscles are torn or the parametria are damaged, surgical revision may be necessary.