The excretion of end products of the body's metabolism, within which urine or urine in particular is of central importance, is based on anatomically different structures. They not only collect and filter the urine, but also carry it on until it is finally excreted. In this context, the urethra.
What is the urethra
Schematic representation of the anatomy and structure of the urinary bladder. Click to enlarge.The urethra or urethra belongs to the urinary organs and therefore consists of extremely complex anatomical structures.
The urethra is just one section that makes up the entire lower urinary tract, such as the calyxes, the renal pelvis and the urinary bladder and ureters. The urinary bladder is present in both women and men and, depending on gender, performs additional tasks.
In this context, the urethra in men not only carries urine, but also semen. Differences between the structure of the urethra in women and men can also be seen in their length.
Anatomy & structure
Due to the anatomy of the urethra this shows up in cross section as a hollow tube. This is lined with different tissue areas that are layered on top of each other. These tissues include areas that are both muscular and interspersed with mucous cells.
In anatomy, these have been given the name epithelium, more precisely urothelium. There is also a tightly branched network of blood vessels and nerves in the urethra. The "construction" of the male urethra is particularly important, as it is more muscular than the female urethra. From the anatomical point of view, the beginning of the urethra is directly at the exit of the urinary bladder.
In addition, so-called constrictions and branches can be identified in the male urethra. The female urethra has its mouth between the vagina and the vaginal vestibule. Since the female urethra also contains, but not as strong, muscle tissue as in men, the urethra can nevertheless support limited urinary behavior in the contracted state.
Functions & tasks
In explaining the function of the Urethrae must be proceeded in a differentiated manner, because these differ from one another for women and men.
Nevertheless, the process of emptying the urethra is subject to the same processes. The physiological prerequisites for the urethra are complicated processes that are carried out one after the other like a chain. The starting point of these chain processes is the filled urinary bladder, which sends an impulse to the responsible brain areas via the ingrown nerves.
An increase in the pressure on the inner walls of the urinary bladder leads to an overstretching of the elastic urinary bladder wall tissue. A signal from the brain allows the urinary bladder to contract. The sphincter muscle in the lower zone of the urinary bladder opens and the urine flows through the urethra in a controlled manner.
At the same time the urethra contracts and the urine is squeezed out under more or less great pressure so that a jet is created.
Diseases
The urethra has a very significant influence on urine excretion and can promote incontinence with organic restrictions.
Most people will experience an inflammation of the urethra known as urethritis at some point in their lives. This inflammation is usually triggered by bacteria or fungi that enter the urethra either from the outside or through the kidneys. Another disease of the urethra that carries many risks is cancer of the urethra, which can develop through tumor growth.
Other diseases that can be diagnosed in the urethra are atresia of the urethra in which no urethra is created. In contrast, there is multiple urethral growth. A congenital megaloutrea is a massive enlargement of the urethra and is accompanied by a noticeable curvature of the penis. Equally important are an abnormal shape of the penis due to an abnormal urethral exit and a tight meatus.
Further diseases of the urethra can result from mechanical influences in the form of injuries. Noteworthy are the stress incontinence that occurs primarily in women, as well as the narrowing of the meatus and the caruncle in the urethra. With a urethral caruncle, there is a prolapse of the urethra into the female genital organs. Diverticula due to changes in the urethral glands and fistulas in the urethra are also important.
Typical & common diseases
- Incontinence (urinary incontinence)
- Inflammation of the urethra (urethritis)
- Urethral cancer (less often)
- Urethral stricture
- Frequent urination