Normal female anal structure

The anal structure of normal women and men is different. For women, it is the body's way of excreting waste and the end of the digestive tract, which is divided into the anal canal, rectum, coccyx, uterus, etc., while for men, it is the urethra, prostate and other organs. Therefore, if there is an abnormality in the anus, we can observe the structural components of the anus and then treat it. Now let us understand the anatomical components of the female anus.

The anal canal is the end of the digestive tract. The anatomical structure of the anus extends from the dentate line to the anus (anal margin), and is about 3-4 cm long. Some people extend the upper limit of the anal canal to 1.5 cm above the dentate line, that is, the anorectal ring plane, which is called the surgical anal canal and is rarely used. The surface layer of the anal canal is composed of columnar epithelium and transitional epithelium in the upper section, and transitional epithelium and squamous epithelium in the lower section. The anal canal is adjacent to the urethra and prostate in front of men, and to the uterus and vagina in women; the back is the coccyx, surrounded by internal and external sphincters.

Surrounding clearance

That is, the surgical anatomical space, which is very susceptible to infection and abscess formation because it contains fatty connective tissue. Below the levator ani muscles are:

① The space around the anus is located between the ischioanal diaphragm and the surrounding skin. The left and right sides can communicate with each other behind the anal canal (also called the superficial post-anal space).

② The sciatic interspace (also known as the ischioanal interspace) is located on both sides of the anal canal, below the levator ani muscle and above the ischioanal diaphragm. There is one on each side, which can communicate with each other behind the anal canal (also called the deep post-anal interspace).

Above the levator ani muscles are:

① Pelvic rectal space, one on each side of the rectum, located above the anal levator muscle and below the pelvic peritoneum.

② The retrorectal space is between the rectum and the sacrum and above the levator ani muscle, and is connected to the rectal spaces on both sides of the pelvis.