Urinary System

Various types of waste materials are produced in our body continuously. The byproducts of metabolism and other materials are harmful to our body and must be excreted out. Various body organs like lungs, kidneys, large intestine, skin, etc. are involved in the excretion of such undesirable materials.

Organs taking part in the urinary system are:

1. Kidneys
2. Ureter
3. Urinary bladder
4. Urethra

Kidneys:

A pair of bean-shaped kidneys is located at the rear of the abdominal cavity. They serve the body as a natural filter for the blood and remove wastes which are diverted to the urinary bladder. They are supplied with blood from the renal artery. It filters uric acid, salt, and other waste as urine from the blood while other substances that are useful for the body are retained in the blood.

Ureter:

In the adult, the ureters are usually 25–30 cm (10–12 inch) long and 3–4 mm in diameter. Two separate ureters are joined to the urinary bladder at the other end. Ureter brings waste materials and water filtered by the kidneys to the urinary bladder.

Urinary bladder:

The urinary bladder, which is pear shaped organ, stores urine. It can store about 800 ml of urine. The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. Urine enters the bladder via the ureters and exits via the urethra.

Urethra:

The urethra lies below the urinary bladder. It provides the pathway for the excretion of urine collected in the urinary bladder. In a male, the urethra travels through the penis and carries semen as well as urine. In a female, the urethra is shorter and emerges at the female external urethral orifice above the vaginal opening.