Outline the functions of the kidney.

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College Answer

Outline type questions require a comprehensive list and a brief explanation of each major 
function of the kidney. This should have included water balance, electrolyte balance, 
endocrine function, filtration, metabolism, acid-base balance, excretion and blood pressure 
control.
Adequate breadth was lacking in many answers. Marks were awarded for discussion of 
water reabsorption at specific points along the length of the nephron and the control 
mechanism through Aquaporins and ADH. It was expected answers would include calcium, 
magnesium, glucose and amino acid handling by the kidney (as well as sodium and 
potassium). Better answers discussed the elimination of fixed as well as volatile acids and 
outlined the role of ammonia. Discussion of the endocrine functions would include EPO, 
1,25 dihydroxy-cholecalciferol, prostaglandin E, renin, angiotensin II and kallekrein.
Superficial responses such as, “the kidney is important in regulating volume” (or “waste” or 
“water” or “sodium”) were not sufficient.