Urethra Structure, Parts, Functions and Diseases and Disorders
In this Article You Will Learn:
- What is the difference between the ureter and the urethra?
- How the job of urethra is twofold in the human males?
- What brings urination under your voluntary control?
Sounding similar, the ureter and urethra are often confused with each other. Both carrying urine for excretion, each has a different location and connection in the body. While the ureter runs from the kidney to the urinary bladder, the urethra runs from the bladder to the external urethral orifice. It is also pertinent to note that there are two ureters and a single urethra in your body.
Urethra in Brief:
It is this canal, carrying the excretory fluids, that opens to the exterior of the body.
The length of urethra varies greatly across genders, that is, females and males. In the former, it is much shorter, while in the latter, it is around four times longer.
The body wall is composed of three distinct layers that are continuous with the urinary bladder.
The urethra is vulnerable to several inflammatory, infectious, genetic, and STDs (Sexual Transmitted Disorders) diseases.
For example, urethritis is the inflammation of urethra which commonly occurs because of a bacterial infection. You can typically cure it with antibiotics as prescribed by your healthcare provider.
Parts of Urethra
If you dissect and view the urethra parts, you can make distinction between three layers, viz. mucous, erectile and muscular.
It shows considerable variation based on gender differences, i.e. in women, it ranges between 3.5 to 5.0 centimetre, while in males, it varies from 15 to 20 centimetre.
This is because, in women, it travels only a shorter distance to empty into the region between clitoris and vagina and extends from the internal to the external urethral orifice.
Difference Between Male and Female Urethra
|Length: 18-20 cm||Length: 3.5-5 cm|
|Functions: (i) Urination (ii) Ejaculation of Semen||Functions: Only Urination|
|Course: Curved (Double)||Course: Nearly Straight|
|Foley Cathetarisation is Difficult||Foley Cathetarisation is Easy|
In case of men, on the other hand, it covers comparatively longer distance to reach the end of male genital organ.
However, to make the concept clear, the urethral tube can be divided into four distinct parts which are named after their respective location, namely, spongy, membranous, pre-prostatic and prostatic urethra.
Functions of Urethra
In human males and females, as is the case with its structural variation, you will see different urethra functions.
In women, the urinary tube serves only as a passage for urine from bladder to the region near clitoris and vagina.
While in men, it is involved in dual functions, that is, the transfer of urine out of the body through penile opening as well as the ejaculation of seminal fluid.
The process of urination is controlled by both voluntary and involuntary actions where the external urethral sphincter is responsible for the deliberate command over the excretion of urinary fluid.
The striated muscle tissue that forms the external voluntarily controlled sphincter is responsible for the effective functioning of this structure.
Diseases of Urethra
Urine tests, cystoscope and x-Ray techniques are used to determine the critical disorders of this organ.
If timely diagnosed, they can be easily cured. But, due to the location of the infection at the sensitive region, the patients are usually very shy to disclose the matter to their health care provider.
Some common medical conditions of the structure include urethral stricture, cancer, inflammation, infections, sexually transmitted disorders, inherited abnormalities, and so on.
Urethritis is caused by microbial infections and leads to swelling in the boundary wall of the urinary tube. The narrowing of the opening of urethra is termed as urethral stricture.
Some of the common symptoms in many of these disorders are severe pain, difficulty in passing urine, discharge and bleeding, etc.
Medications and surgical therapy are the frequently recommended treatment measures, but the choice depends upon the type and the severity of the disorder.
In case of urethral cancer, the cells in the organ start growing abnormally and out of control. The causes of this rare form of cancer are least known.
Individuals over age 60 and those suffering from bladder cancer are at the higher risk of developing this condition. It may be treated with radiation, chemotherapy and surgery.
Interesting Urethra Facts:
- Did you know the length of urethra significantly varies across genders? Measuring just around 5cm in human females, it runs for the length of 20 cm in males – four times longer!
- While females use it just for urination, the job of urethra is twofold in males, i.e. urination as well as ejaculation.
- Composed of a striated muscle, it is the external urethral sphincter which brings urination under your voluntary control.
- During urination, mechanical force and electrical signalling in the smooth muscle cells of the urethra work in an organized and unitary fashion to expel the urine outside the body.
- Urethral cancer may be of different types, such as adenocarcinoma, transitional cell carcinoma, and squamous cell carcinoma.