The urinary system, also known as the renal system, is a group of organs and structures that work together to remove waste products from the body and regulate the balance of fluids and electrolytes in the blood. The main organs of the urinary system are the kidneys, ureters, bladder, and urethra.

The kidneys are two bean-shaped organs that are located on either side of the spine, just below the ribcage. They filter waste products from the blood and produce urine, which is passed through the ureters to the bladder for storage.

The ureters are long, muscular tubes that connect the kidneys to the bladder. They transport urine from the kidneys to the bladder by squeezing rhythmically to force urine down the tubes.

The bladder is a muscular sac that is located in the pelvis. It stores urine until it is ready to be eliminated from the body. The bladder can expand and contract as urine is produced and stored.

The urethra is a tube that connects the bladder to the outside of the body. It carries urine out of the body during urination. In males, the urethra also serves as a passage for semen during ejaculation.

The urinary system plays an important role in maintaining homeostasis, or the balance of fluids and electrolytes in the body. It eliminates waste products, such as urea and creatinine, from the blood and regulates the levels of ions such as sodium, potassium, and calcium. Disorders of the urinary system can cause a variety of symptoms, ranging from mild discomfort to life-threatening complications. These disorders may include urinary tract infections, kidney stones, and kidney failure.