Answer to Question 1
Increased secretion of parathyroid hormone helps to prevent elevations in serum phosphate but contributes to bone loss and the development of renal osteodystrophy, a bone disorder common in renal patients. Electrolyte imbalances are likely when the GFR is very low (below 5 milliliters per minute), when hormonal adaptations are inadequate, or when intakes of water or electrolytes are either very restricted or excessive. Because the kidneys are responsible for maintaining acid-base balance, acidosis often develops in chronic kidney disease. Although usually mild, the acidosis exacerbates renal bone disease because compounds in bone (e.g., protein and phosphates) are released to buffer the acid in blood.
Answer to Question 2
A