Key features of the urinary system:

Kidneys

• Paired, right is lower than left
• Hilum is medial cleft for vessels and ureters to pass
• Supplied by renal artery and vein
• Filter the blood to produce urine

Ureters

• Carry urine away from the kidneys, to the urinary bladder

Urinary bladder

• Lies within the pelvis
• Stores and expels urine

Urethra

• Carries urine to the external environment
• Orifices are regulated by internal and external sphincters

Regulatory functions

• Regulates blood volume, and indirectly, blood pressure; in dialysis patients, the amount of blood volume removed has a significant impact on their blood pressure.
• Regulates erythrocyte production
• Regulates ion balance, and, therefore, the acid/base balance (pH) of the blood.

Clinical Correlations:

• Urinary tract infections (UTI) are one of the most common forms of infection and can involve any part of the urinary system; infection that spreads to the kidneys, called pyelonephritis, can have serious health consequences.
• Kidney stones are hard mineral deposits that form within the kidney and pass through the urinary system; they can be quite painful, and if they become lodged, they may require surgical extraction.