Final answer:
An abnormal narrowing of the urethra is termed urethral stricture. This condition can affect the passage of urine and semen in males and is more frequently seen in males due to a longer urethra. The urethra has different regions and is lined by various types of epithelia, with sphincters controlling urine flow.
Step-by-step explanation:
The medical term for an abnormal narrowing of the urethra is urethral stricture. This condition can be caused by various factors including urethral tumors, urinary bladder tumors, and an enlargement of the prostate gland, especially in the male urethra.
The urethra is a crucial part of the urinary system, which transports urine from the bladder to the outside of the body. In a person with XY chromosomes (male), the urethra also transports semen. The male urethra is divided into four regions: the preprostatic, the prostatic, the membranous, and the spongy urethra. Conditions such as urethral stricture could hinder the flow of urine and semen, causing various complications.
In persons with XX chromosomes (female), the urethra is significantly shorter, averaging about 4.8 cm long, which contributes to a higher incidence of urinary tract infections in females due to easier access for bacteria. Various parts of the urethra are lined by different epithelia, with transitional epithelium near the bladder and nonkeratinized, stratified squamous epithelium towards the external orifice. Urinary sphincters help control the release of urine.