What is the structural unit of the kidney responsible for urine formation?

The nephron is the structural and functional unit of the kidney that is primarily responsible for the formation of urine. Each kidney contains approximately one million nephrons that work together to filter blood and remove waste products while reabsorbing essential substances.

The nephron comprises several key components: the glomerulus, where the initial filtration of blood takes place, the renal tubules, which are responsible for the reabsorption and secretion of substances, and the collecting ducts, which ultimately drain urine into the renal pelvis. The combined actions of these regions within the nephron lead to the production of urine by concentrating waste products and conserving water and electrolytes.

Understanding the nephron's structure and function is crucial for grasping how the kidneys maintain homeostasis in the body, regulate blood pressure, and balance fluid and electrolytes. Other anatomical structures like the glomerulus, renal pelvis, and ureter play supportive roles but do not carry out the urine formation process themselves.