Acid-Base, Potassium, Divalent Ion Regulation
By the end of the week, students will be able to:
Acid-Base
- Differentiate simple acid-base disorders.
- Explain the concept of buffer systems.
- Define components of the Henderson-Hasselbalch equation.
- Define renal net acid excretion
- Discuss the role of renal net acid excretion in acid-base homeostasis.
- Explain renal transport mechanisms involved in bicarbonate reclamation, ammonium, excretion, and generation of “new” bicarbonate.
- Identify factors that regulate renal bicarbonate reabsorption and net acid excretion, such as extracellular fluid volume, pCO2, aldosterone and other neurohormones, and systemic acid-base status.
- Differentiate an anion-gap metabolic acidosis from a hyperchloremic metabolic acidosis and identify common etiologies of anion-gap acidosis.
- Analyze mechanisms involved in the generation and maintenance of metabolic alkalosis.
Potassium
- Define normal extracellular potassium concentration values.
- Assess the role of the kidney in potassium homeostasis.
- Discuss filtration, reabsorption, and secretion of potassium by the kidney in normal states.
- Identify and explain cellular mechanisms responsible for alteration or regulation of potassium excretion.
- Assess the role and transport mechanisms whereby aldosterone increases potassium excretion.
- Analyze the effects of potassium on acid-base status and renal ammonium excretion.
- Assess the adverse consequences and treatment of hypo- and hyperkalemia.
Calcium and Phosphate
- Define normal serum values of calcium and phosphate.
- Discuss major hormonal systems regulating serum calcium and phosphate concentrations, with emphasis on parathyroid hormone (PTH) and 1,25-dihydroxycholecalciferol (active form of vitamin D).
- Explain sites and mechanisms of renal handling of calcium and phosphate.
- Discuss the cellular mechanisms of renal tubule calcium and phosphate transport, including pumps, co-transporters, exchangers, channels, and diffusive (passive) pathways.
- Differentiate the effects of loop diuretics and thiazide diuretics on renal calcium excretion and plasma calcium concentration.
- Discuss the role of FGF23 and Klotho in regulation of renal phosphate excretion and phosphate homeostasis.