The urethra is a hollowed tubular organ through which urine is expelled from the body. This structure extends from the bladder to the external opening, allowing urine to be released.
The anatomy of the urethra differs between males and females. In females, the urethra is short, measuring about 3–4 cm in length, and opens anterior to the vaginal opening. In males, the urethra is longer and passes through the penis, serving dual purposes: expelling urine and ejaculating semen. The male urethra is divided into three distinct regions:
Both males and females have two sphincters that regulate the flow of urine:
The urethra is essential for the excretion of urine and, in males, for the ejaculation of semen. Understanding the anatomy and function of the urethra is crucial for diagnosing and managing conditions such as urinary tract infections, incontinence, and other disorders of the urinary system.
The urethra is a tube-like structure extending from the lower end of the urinary bladder to the external opening for releasing urine out of the body.
In females, the urethra is short and opens just above the vaginal opening, while in males, it traverses through the penis.
The widest region of the male urethra is the prostatic region, passing through the prostate gland below the bladder, followed by the short membranous urethra.
The spongy urethra, the longest part ending in the external urethral orifice, extends through the length of the penis and is surrounded by erectile tissue.
Besides urine, the male urethra also ejaculates semen.
In both sexes, the circular fibers of the detrusor smooth muscle at the bladder-urethra junction thicken to form the internal urethral sphincter.
It is controlled by the autonomic nervous system, preventing urine leakage and maintaining bladder continence.
Another circular band of skeletal muscle surrounds the urethra as it passes through the urogenital diaphragm, forming the external urethral sphincter.
It is under conscious control, allowing voluntary initiation or withholding of urination.
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