Ureter vs Urethra
The urinary system is basically made up of kidneys, ureters, bladder and urethra. The main function of this system is the process of excretion. It excretes the waste products of metabolisms and other materials in the form of urine. Also, the system is important to maintain homeostasis by regulating the amount of water and salt that is excreted in urine. Both urethra and ureters are fibromusclular tubes that conduct urine in the urinary system.
Ureter
Ureters are fibromuscluar tubes that propel urine from kidneys to the urinary bladder. The smooth muscles can make involuntary wave like contractions and propel urine towards the urinary bladder. This series of organized muscle contraction is known as peristalsis. In an adult, ureter is about 25 to 30cm long and about 3 to 4mm in diameter. The upper half of the ureter is in the abdomen proper while the lower half is in the lateral pelvic wall. In males, the ureters lie in the sacorgenital fold and are crossed medially by the ductus deferens. In females, ureters lie in the uterosacral ligament and are crossed anteriorly by the uterine artery. The ureter is embedded for about 2cm in the back side wall of urinary bladder. The lumen of the ureter is narrowest and muscular coats of the ureter and bladder are continuous.
Urethra
Urethra is a fibromuscular tube that excretes urine from the bladder to the exterior. It begins at the neck of the bladder and ends at the external urethral orifice. Urethra is lined with cell layers that can secrete mucous, and the muscular layer is important to conduct the urine through the tube. Basically there are few differences between male and female urethra. Male urethra is much longer than female urethra as it extends the length of the penis. Male urethra, about 20cm in length, comprises three parts; prostatic, membranous, and spongy.
Prostatic urethra runs from the bladder to the part of the urethra where the vas deferens connects. Membranous urethra runs through the urinary sphincter, and the last part, spongy urethra runs though the length of the penis. The spongy urethra is stretchy, because it allows for erections of penis in the reproduction process. Unlike the female urethra, male urethra is considered as a part of both the urinary and reproduction system. Female urethra is about 4cm long and fused with the anterior wall of the vagina.
What is the difference between Ureter and Urethra?
• Urethra is the last part of the urinary system, whereas ureters are located at the middle of the urinary system.
• An adult human has two uterers and one urethra.
• Ureter propels urine from kidneys to the urinary bladder, while urethra passes urine from the urinary bladder to exterior.
• In males urethra is considered as a part of both the reproductive and urinary system, whereas ureter is considered as a part of the urinary system.
• Normally, ureter is longer than urethra, but urethra has a larger diameter than ureters.
• The smooth muscles in ureters can produce contractions using peristalsis, unlike muscles in urethra.