overview of Filtration, reabsorption, and secretion

  1. filtration (Bowman’s capsule)

    • Blood enters through the afferent arteriole

    • Fluid and solutes from the blood pass through podocytes into the Bowman’s capsule

    • The remaining blood leaves the efferent arterial light in the filtrate and continues into the renal tubule

  2. Reabsorption (proximal, near, convoluted tubule, and loop of Henle)

    • Most of the water (80%) and many ions in nutrients are reabsorbed into the blood

  3. Secretion (distal, far, convoluted tubule)

    • Additional substances are actively removed from the blood (H+, drugs, steroids)

    • Fine-tuning of the K+ and H+ in the urine to regulate blood pH