The urethra is the connection between the bladder and the external urinary opening.


Latin: urethra


The location and course of the urethra differ considerably between men and women. Both have in common that they are a connecting piece between the urinary bladder (Vesica urinaria) and the external urinary opening on the genitals. It is covered by a special mucous membrane of the urinary tract, which also contains the bladder, ureter (Ureter) and renal pelvis (Pyelon) lines.

The female urethra (urethra feminina)

The female urethra is just 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 Scabbard (vagina) in the small pelvis. She steps through the pelvic floor, a triple layer of muscle in the pelvis. It flows into the external urinary outlet (Ostium urethrae externum) between the little ones Labia just behind the clitoris (clitoris) and thus in front of the vaginal entrance.

Due to the straight course of the female urethra, it is relatively easy to use one Urinary catheter to supply, if e.g. required for an operation.

Since the female urethra is very short, bacteria from the vagina or rectum can quickly rise into the urinary bladder and cause cystitis.

Figure ureter: A - cross section in relaxed state and B - retroperitoneal space with ureters (red)
  1. Ureter - Ureter
  2. Transitional epithelium - Urothelium
  3. Shift layer of the
    Mucous membrane - Lamina propria
  4. Inner longitudinal layer -
    Stratum longitudinal internum
  5. Outer longitudinal layer -
    Stratum longitudinal externum
  6. Middle ring layer -
    Circular stratum
  7. Connective tissue covering with
    Blood vessels - Tunica adventitia
  8. Aortic fork - Aortic bifurcation
  9. Rectum - Rectum
  10. Urinary bladder - Vesica urinaria
  11. Adrenal gland -
    Glandula suprarenalis
  12. Right kidney - Ren dexter
  13. Renal pelvis - Pelvis renalis
  14. Lower vena cava - Inferior vena cava

You can find an overview of all Dr-Gumpert images at: medical illustrations

The male urethra (urethra masculina)

The male urethra is approx. 20 cm long and therefore significantly longer than the female. In contrast to the female urethra, the male urethra is simultaneous Urinary and sexual tract, as the semen and the products of the sex glands empty through the urethra.

The man's urethra has its origin (Ostium urethrae internum) as well as the female on the bladder neck. Then follow four anatomical sections:

  1. First, the male urethra crosses the internal sphincter of the bladder (Pars intramuralis). There you can find the first bottleneck. It then runs through the prostate gland (prostate) of the man where it widens slightly (Pars prostatica). The ducts of the prostate and seminal vesicle flow here.
  2. Then the urethra runs through the pelvic floor, more precisely through the external sphincter (Pars membranacea). Here you can find the second bottleneck the urethra.
  3. The longest section of the urethra now runs in the Cavernous urethra of penis (Part of the cancellous bone), where there are two widenings. The urethral glands also flow here (Bulbourethral glands) into the urethra. Finally the urethra joins the Acorn (Ostium urethrae externum).

Since the male urethra is in two curves runs and three bottlenecks a urinary catheter is much more difficult to insert. You can help yourself by pulling the penis straight for catheterization so that you can at least straighten the curvature in the penis.

Because of the length of the male urethra, men are less likely to suffer from bladder infections than women, but kidney stones can more easily get caught in the tightness and curvature, which can lead to renal colic.

Blood supply

The urethra is made up of branches of the deep pelvic artery (Internal iliac artery) supplied with arterial blood. This large artery divides into the Pudendal artery on. This in turn has many finer end branches, one of which is the so-called Urethral artery (Urethral artery), which ultimately pulls towards the urethra.

The venous outflow takes place via the Urethral veinwhich in turn over the slightly larger Pudendal vein in the deep pelvic vein (Internal iliac vein) opens.


To Continence, so the ability to hold the urine, on the one hand you need a The bladder sags and on the other hand the intact internal sphincter at the transition from the bladder to the urethra (Internal urethral sphincter muscle). The sphincter is also supported by part of the muscular pelvic floor (External urethral sphincter muscle). Is this pelvic floor too limp, as it has been after several Births is often the case, the patient is unable to hold the urine and Incontinence under stress (e.g. when laughing, climbing stairs).

The urethra has its own nerve supply with autonomic nerve branches. These form a Nerve plexus (Vesical plexus) in the small pelvis.

In order to initiate micturition (urination), on the one hand, a signal is sent via the nerves to the brain that the bladder is filled to a certain extent and that the impression of a “need to urinate” can arise. On the other hand, the brain can also voluntarily initiate emptying of the bladder. The bladder muscle (detrusor vesicae muscle) is tensed and the two bladder sphincters relax. The inner sphincter is controlled by the autonomic nervous system and is therefore independent of the will. The external sphincter is controlled by the central nervous system - i.e. the brain - and can therefore relax depending on the will. Of the urine enters the urethra, which by means of gravity transports urine towards the external urinary outlet.

Urethral diseases

Inflammation of the urethra (urethritis)

The inflammation of the urethra (urethritis) is an inflammation of the mucous membrane of the urethra. A distinction is made between gonorrhea (gonorrhea) from non-gonorrhoeic urethritis. The former is caused by the bacterium Neisseria gonorrhoea, the latter mostly by chlamydia. These are typical diseases that can be transmitted through unprotected sexual intercourse. Urethritis presents with purulent discharge, itching, and burning sensation when urinating. The doctor takes a swab from the urethra to detect the bacterium and gives antibiotics for therapy.

Hypo- / epispadias

It is a relatively common one congenital malformation the male urethra. In hypospadias, the urethra joins the bottom of the penis, with epispadias on the Top of the penis. It should be a operative correction in the 1st or 2nd year of life respectively.

Inflammation of the bladder (cystitis)

A very common disease is the Cystitis This occurs mainly in women, since the urethra is significantly shorter here. It can cause bacteria to rise, mostly Escherischia coli from the intestines, which travel through the urethra into the bladder. Patients usually have increased need to urinate already at small amount of urine, Painful urination, Blood in the urine and Lower abdominal pain.
Therapy of choice is one one to three days of antibiotic therapy. The dangers are on the one hand a repeated occurrence of the cystitis, on the other hand with weakened immune system, the germs ascend via the ureters into the renal pelvis and above it to one Pelvic inflammation (Pyelonephritis).

Benign prostatic hyperplasia

A great many men in middle to older age have one benign enlargement the prostate gland (prostate). Since the man's urethra runs through the prostate, pressure and pressure quickly develop Narrowing of the urethra (Urethral stricture). The patient then suffers from one weak urine stream, frequent urination, Urinary stutter, Residual urine sensation and Trickle down after urinating.

The complication is that the prostate narrows the urethra so that it becomes one Urinary retention comes. The patient has a strong overextended bladderbut can no longer urinate because of the obstacle. An instant relief over one catheter is absolutely necessary!