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6.2.3. Urinary tract

Urinary tract

The urinary tract are the tubes that carry urine from the kidneys to the outside. The urinary tract are:

  • The ureters are two tubes of about 25-30 cm that collect urine from each kidney and carry it from the renal pelvis to the urinary bladder.
  • The urinary bladder is an elastic bag, with muscular walls, in which urine that continuously arrives through the ureters is stored. When the bladder is full, the nervous system receives the signal that its emptying is necessary (urination reflex), proceeding to urinate, being expelled to the outside through the urethra .
  • The urethra is the tube that communicates the urinary bladder with the outside. It has a sphincter (ring-shaped muscle) at the beginning, which you need to open in order to urinate. Control of this sphincter is not innate, and you learn to control it with age .

In men, the urethra joins the vas deferens of the reproductive system, so it is common to the urinary and reproductive systems, expelling urine and semen, respectively. In the case of women, the urinary tract is independent of the reproductive one. The urethra in men is longer than in women, as it runs through the inside of the penis.

Vías urinarias: la orina sale de los riñones por los uréteres hacia la vejiga urinaria, donde se almacena hasta que se expulsa por la uretra

By Regalafar (Own work) [Public domain], via Wikimedia Commons