What are the characteristics of the female urethra?

The special structure of women's genitals can easily lead to some inflammations, such as urethritis. This is mainly because the urethra is relatively short and has no bends, so if you are not careful, some infections may occur.

1. Female urethra

The female urethra is very short, only 2.5-5 cm long, with an average of 3.5 cm, and a diameter of about 8 mm. It is easy to expand and can reach 10-13 mm. It has no bends and starts from the bladder neck and runs downward and forward to the urethral opening behind the pubic symphysis in front of the vagina.

2. Composition

The female urethra can be divided into three parts: upper, middle and lower: the tissue structure of the upper part is consistent with the bladder neck. The circular muscle of the bladder neck is continuous with the circular muscle of the upper urethra and is particularly thickened at the neck, which is different from the sphincter of the male bladder neck, which is composed of the left and right middle and outer layer muscle fibers crossing each other. Female internal sphincter,

It is composed entirely of circular smooth muscle fibers that surround the entire bladder neck and upper urethra. Therefore, the action of the internal sphincter is particularly strong in women. In the middle urethra, there are voluntary circular muscles outside the smooth muscle layer. Although this muscle layer is not very obvious, it also has some external sphincter function. The lower urethra, which is the urethral opening, has no muscles, only two layers of triangular ligament fibrous tissue. In addition, the levator ani muscles, deep perineal muscles and triangular ligament also play an auxiliary role in controlling female bladder urine.

3. Organization

The mucosal epithelium in the middle and outer parts is a quadratic epithelium similar to the vaginal mucosa, and the upper part transforms into the same transitional epithelium as the bladder neck. There is loose tissue between the submucosal layer and the muscle layer, and outside the muscle layer there is a rich venous network tissue, namely the urethral spongy tissue. Urethral glands are abundant in the female urethra, the most prominent of which are the paraurethral glands, which contain columnar epithelium that secretes mucus.

Lymph of the urethra: There are many lymphatic vessels and lymph glands under the urethral mucosa, which drain the lymph to the inguinal and subgastric lymph nodes on both sides.

Blood supply to the urethra: The inferior vesical artery supplies the upper urethra, the vaginal artery supplies the middle urethra, and the internal pudendal artery supplies the lower urethra. The veins return to the bladder, vagina, and pudendal venous plexus.

Physiology of the urethra: The main function of the female urethra is to urinate and secrete mucus; the urethral gland is also an accessory gland that secretes transparent protein-containing mucus, which serves to increase lubrication during sexual intercourse.