Male urethra

In the human male, the urethra is about 8 inches (20 cm) long and opens at the end of the penis. The urethra provides an exit for urine as well as semen during ejaculation.
The urethra is divided into four parts in men, named after the location:

Region Description Epithelium
pre-prostatic urethra This is the intramural part of the urethra and varies between 0.5 and 1.5 cm in length depending on the fullness of the bladder.
prostatic urethra Crosses through the prostate gland. There are several openings: (1) the ejaculatory duct receives sperm from the vas deferens and ejaculate fluid from the seminal vesicle, (2) several prostatic ducts where fluid from the prostate enters and contributes to the ejaculate, (3) the prostatic utricle, which is merely an indentation. These openings are collectively called the verumontanum. Transitional
membranous urethra A small (1 or 2 cm) portion passing through the external urethral sphincter. This is the narrowest part of the urethra. It is located in the deep perineal pouch. The bulbourethral glands (Cowper's gland) are found posterior to this region but open in the spongy urethra. Pseudostratified columnar
spongy urethra (or penile urethra) Runs along the length of the penis on its ventral (underneath) surface. It is about 15–16 cm in length, and travels through the corpus spongiosum. The ducts from the urethral gland (gland of Littre) enter here. The openings of the bulbourethral glands are also found here. Some textbooks will subdivide the spongy urethra into two parts, the bulbous and pendulous urethra. Pseudostratified columnar – proximally, Stratified squamous – distally

The length of a male's urethra, and the fact it contains a prominent bend, makes catheterization more difficult. The integrity of the urethra can be determined by a procedure known as retrograde urethrogram.

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