The main difference between Ureter and Urethra is that the Ureter is a tubes used in the urinary system in most animals and Urethra is a tube that connects the urinary bladder to the external urethral orifice
The ureters are tubes made of smooth muscle fibers that propel urine from the kidneys to the urinary bladder. In the human adult, the ureters are usually 25–30 cm (10–12 in) long and around 3–4 mm (0.12–0.16 in) in diameter. The ureter is lined by urothelial cells, a type of transitional epithelium, and has an additional smooth muscle layer in the more distal one-third to assist with peristalsis.
In anatomy, the urethra (from Greek οὐρήθρα – ourḗthrā) is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra connects to the urinary meatus above the vagina, whereas in marsupials, the female’s urethra empties into the urogenital sinus.Females use their urethra only for urinating, but males use their urethra for both urination and ejaculation. The external urethral sphincter is a striated muscle that allows voluntary control over urination. The internal sphincter, formed by the involuntary smooth muscles lining the bladder neck and urethra, is innervated by the sympathetic division of the autonomic nervous system. The internal sphincter is present both in males and females.
Either of the two long, narrow ducts that carry urine from the kidneys to the urinary bladder.
The tube through which urine exits the body and, in penises, through which semen is ejaculated.