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Renal, Fluids, and Electrolytes (RFE): Week 3

Resources for the RFE course

Weekly Objectives

Acid-Base, Potassium, Divalent Ion Regulation

By the end of the week, students will be able to:

Acid-Base

  1. Differentiate simple acid-base disorders.
  2. Explain the concept of buffer systems.
  3. Define components of the Henderson-Hasselbalch equation.
  4. Define renal net acid excretion
  5. Discuss the role of renal net acid excretion in acid-base homeostasis.
  6. Explain renal transport mechanisms involved in bicarbonate reclamation, ammonium, excretion, and generation of “new” bicarbonate.
  7. 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.
  8. Differentiate an anion-gap metabolic acidosis from a hyperchloremic metabolic acidosis and identify common etiologies of anion-gap acidosis.
  9. Analyze mechanisms involved in the generation and maintenance of metabolic alkalosis.

Potassium

  1. Define normal extracellular potassium concentration values.
  2. Assess the role of the kidney in potassium homeostasis.
  3. Discuss filtration, reabsorption, and secretion of potassium by the kidney in normal states.
  4. Identify and explain cellular mechanisms responsible for alteration or regulation of potassium excretion.
  5. Assess the role and transport mechanisms whereby aldosterone increases potassium excretion.
  6. Analyze the effects of potassium on acid-base status and renal ammonium excretion.
  7. Assess the adverse consequences and treatment of hypo- and hyperkalemia.

Calcium and Phosphate

  1.  Define normal serum values of calcium and phosphate.
  2. 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).
  3. Explain sites and mechanisms of renal handling of calcium and phosphate.
  4. Discuss the cellular mechanisms of renal tubule calcium and phosphate transport, including pumps, co-transporters, exchangers, channels, and diffusive (passive) pathways.
  5. Differentiate the effects of loop diuretics and thiazide diuretics on renal calcium excretion and plasma calcium concentration.
  6. Discuss the role of FGF23 and Klotho in regulation of renal phosphate excretion and phosphate homeostasis.