Kidneys and acid base regulation in human body | Physiology | by Imran Yaseen

The kidneys play a crucial role in maintaining the body's acid-base balance, which is essential for optimal physiological function. Here's how they contribute to acid-base regulation: *1. Acid Secretion and Base Reabsorption:* The kidneys regulate blood pH by secreting hydrogen ions (H+) into the urine and reabsorbing bicarbonate ions (HCO3-) back into the bloodstream. Proximal Tubule: Hydrogen ions are actively secreted into the tubular fluid, while bicarbonate ions are reabsorbed into the bloodstream. Distal Tubule and Collecting Ducts: Further adjustments to acid-base balance occur through the secretion of hydrogen ions and reabsorption or generation of bicarbonate ions. *2. Bicarbonate Reabsorption:* Bicarbonate ions are filtered by the glomerulus and reabsorbed in the proximal tubule. This reabsorption process helps maintain plasma bicarbonate levels and contributes to the body's buffering capacity against acidosis. *3. Ammonia Production:* The kidneys produce ammonia (NH3) from the metabolism of glutamine. Ammonia combines with hydrogen ions in the renal tubules to form ammonium ions (NH4+), which are excreted in the urine, contributing to acid secretion. *4. Acid Excretion:* Hydrogen ions are excreted into the urine primarily as free ions or bound to buffers such as phosphate or ammonia. This process helps eliminate excess acid from the body and regulates blood pH. *5. Acid-Base Disorders:* The kidneys play a critical role in compensating for acid-base imbalances, such as metabolic acidosis or alkalosis. In metabolic acidosis, the kidneys increase acid secretion and bicarbonate reabsorption to restore pH balance. In metabolic alkalosis, the kidneys decrease acid secretion and bicarbonate reabsorption to reduce blood pH. *6. Hormonal Regulation:* Hormones such as aldosterone and angiotensin II play roles in regulating renal acid-base balance. Aldosterone stimulates hydrogen ion secretion and potassium reabsorption in the distal tubules, influencing acid-base balance. Overall, the kidneys' ability to regulate acid-base balance is vital for maintaining normal physiological function and preventing the development of acidosis or alkalosis. Dysfunction of the kidneys can lead to severe acid-base disturbances and contribute to various health problems. Kidneys play important role in balancing the pH of our body by reserving the bicarbonate ions and secreting hydrogen ions and vice versa if required. It is interesting how it manages this all to learn this attend this lecture and ask questions if any #metabolicAcidosis #metabolicAlkalosis #Acid_Base_regulation