Transcript of the deep muscles of the pelvic floor video clip

This shows the deep muscles of the pelvic floor, which are collectively called the levator ani. These are viewed from below.

Each levator ani is a broad sheet of muscles, which varies is thickness and is attached to the inner surface of the true pelvis. It is divided into three pairs of muscles according to their attachments, namely the:

1. Ischiococcygeus 2. Illiococcygeus 3. Pubococcygeus

From its broad origin the levator ani muscle fibres sweep downwards, backwards and medially to be inserted into the upper vagina, perineal body, the anal canal, the anococcygeal body and the lateral border of the coccyx and lower part of the sacrum.

The levator ani muscles form a strong sling to support the pelvic organs and to counteract any increase in abdominal pressure when coughing or lifting, which helps to maintain continence.

The pubococcygeus muscle is the most important part of the levator ani, both in size and function. It arises from the inner surface of the superior ramus of the pubic bones and from the anterior part of the obturator fascia, and sweeps backwards to form U-shaped structures around the urethra, vagina and anorectal junction. The muscle fibres pass downwards and backwards below the bladder and on either side of the urethra, upper vagina and anal canal posteriorly to be inserted into the anococcygeal body and the coccyx. Some fibres terminate in the central tendinous point of the perineal body and others merge with the longitudinal muscle of the rectum. The main function of the pubococcygeus muscles is to provide support to the urethra, vagina and rectum. It also aids micturition and defecation.