Muscles Closing the Pelvic Outlet

The pelvis and abdominal cavity are analysed as two separate regions, although they are a continuation of each other. The bony skeleton formed by the coxae, sacrum and coccyx is characterised as the pelvis. This bony skeleton acts as a bridge between the trunk and lower extremities. The pelvic skeleton is bowl-shaped and contains part of the digestive system, the last parts of the urinary system and the internal reproductive organs. It has a structure that supports the intra-abdominal organs. It also plays an important role during pregnancy and labour. Since it forms the bone canal through which the foetus passes, its size in women is of extra importance. This skeletal system, which is mainly composed of bones and ligaments, is completed with fascia and muscles filling the upper and lower parts. The right and left levator ani muscle and the right and left coccygeus muscles cover the base of the pelvic skeleton and form the pelvic diaphragm. The part above the pelvic diaphragm is called the pelvic cavity and the part below is called the perineum. The perineum is a quadrangular area formed by the structures that close the pelvic outlet. This region differs in men and women. The perineum is analysed in two parts: the urogenital triangle and the anal triangle. The pelvis and perineum are as clinically important as the organs it contains as well as the muscles involved in its structure. The superficial/deep transverse perineal, bulbospongiosus, ischiocavernosus, compressor urethra and external urethral sphincter muscles close the urogenital triangle. In the anal triangle is the external anal sphincter. Many clinical pictures such as urinary stress ıncontinence, fracture of the pelvis, urethrocele, cystocele, uterine prolapse are examined in the clinical anatomy of this region.