Synonyms
Latin: Urethra
Anatomy
The position and course of the urethra differ considerably between men and women. Both have in common that it is a connecting piece between the bladder (vesica urinaria) and the external urinary opening at the genitals. It is covered by a special mucous membrane of the urinary tract, which also lines the bladder, ureter and renal pelvis (pyelon).
The female urethra (Urethra feminina)
The female urethra is only about 3-5 cm long and runs straight. It has its origin at the lower end of the bladder, the bladder neck, and then runs downwards directly in front of the vagina in the small pelvis. It passes through the pelvic floor, a three-layer muscle layer in the pelvis.
It opens with the external urinary outlet (ostium urethrae externum) between the labia minora just behind the clitoris and thus in front of the vagina entrance. Due to the straight course of the female urethra, it is relatively easy to supply it with a bladder catheter, if, for example, an operation is required. Since the female urethra is very short, bacteria can quickly rise from the vagina or rectum into the bladder and cause cystitis.
The male urethra (Urethra masculina)
The male urethra is about 20 cm long and thus considerably longer than the female. In contrast to the female urethra, the male urethra is simultaneously the urinary and genital tract, since the semen and the products of the gonads are emptied via the urethra. The male urethra has its origin (Ostium urethrae internum) just like the female at the bladder neck.
This is followed by four anatomical sections: Since the male urethra runs in two curves and has three narrowing points, a bladder catheter is much more difficult to insert. One helps oneself by pulling the penis straight for catheterization, so that at least the curvature in the penis can be straightened. Due to the length of the male urethra, men are not as often affected by cystitis as women, but kidney stones can get caught in the narrowness and curvature of the urethra, which can lead to kidney colic.
- First, the male urethra crosses the inner sphincter of the bladder (pars intramuralis). This is where the first constriction is found. It then runs through the prostate gland of the man, where it widens slightly (pars prostatica).
This is where the excretory ducts of the prostate gland and seminal vesicle open out.
- Then the urethra runs through the pelvic floor, more precisely through the outer sphincter muscle (pars membranacea). This is the second narrowing of the urethra.
- Now the urethra runs with its longest section in the urethral swelling body of the penis (Pars spongiosa), where there are two widenings. This is also where the urethral onion glands (bulbourethral glands) enter the urethra. Finally, the urethra opens on the glans (ostium urethrae externum).
