Anatomy and Physiology of Children and Adolescents - M. R. Sapin 2007

Urogenital system
Urinary (excretory) system

The Urogenital System comprises the Organs of the URINARY AND REPRODUCTIVE systems, which share a common embryological origin and are closely related through anatomical and functional connections (Figs. 61, 62).

The Urinary Organs include the Kidneys, Ureters, Urinary Bladder, and Urethra. The kidneys are urine-producing organs, while the rest function as Urinary Tract pathways.

The organs of the urinary (renal) system, along with the Digestive System, Lungs, and Skin, eliminate Metabolic waste products from the body that cannot be utilized by human Tissues. The digestive system excretes salts, Bile pigments, Cholesterol, and Water via feces. Carbon dioxide, other gaseous substances, and water are eliminated through the lungs. The sweat and Sebaceous Glands of the skin excrete water (up to 0.6 L per day), carbon dioxide, various salts, and nitrogenous metabolic waste.

Up to 75% of metabolic waste products eliminated from the body are excreted through the kidneys. Urine carries away water, salts, and protein breakdown products (urea, uric acid, etc.). Through the kidneys, the body maintains acid-base balance (pH), a constant and normal volume of water, a steady salt concentration, and stable osmotic pressure. The kidneys work alongside other organs to ensure constancy of the body's internal environment (Homeostasis).



Last update: 10/08/2026

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