URETERS, BLADDER, AND URETHRA

• Ureters - slender tubes 25-30 cm attaching the kidneys to the bladder
• Urinary Bladder - stores urine temporarily; a moderately full bladder is about 5 inches long and holds about 500 mL of urine
• Trigone - triangular region of the urinary bladder base based on three openings (2 openings from ureters (ureteral orifices), 1 opening to the urethra (internal urethral orifice))
• Detrusor muscle - smooth muscle on the wall of the urinary bladder
• Mucosa of the urinary bladder is made of transitional epithelium.
• Urethra - carries urine from the bladder to the outside of the body
• 2 sphincters that control urine release:

  • Internal urethral sphincter - involuntary, smooth muscle
  • External urethral sphincter - voluntary, skeletal muscle
• Length and Location of Urethra:

  Females - 3-4 cm; anterior to vaginal opening

  Males - 20 cm; travels through prostate and penis

  • Prostatic urethra
  • Membranous urethra
  • Spongy urethra