Describe the regulation of plasma calcium concentration.
High scoring answers discussed the three major hormones involved in calcium regulation - parathyroid hormone, vitamin D and calcitonin. For each of these it was expected that candidates include: site of production, stimulus for release, inhibitory factors and actions. In the case of renin it was expected that candidates also include the actions of angiotensin and aldosterone. Very few answers discussed inhibitory factors or negative feedback loops.
Mundy, Gregory R., and Theresa A. Guise. "Hormonal control of calcium homeostasis." Clinical chemistry 45.8 (1999): 1347-1352.
Bronner, Felix. "Mechanisms of intestinal calcium absorption." Journal of cellular biochemistry 88.2 (2003): 387-393.
Davies, K. Michael, Karen Rafferty, and Robert P. Heaney. "Determinants of endogenous calcium entry into the gut." The American journal of clinical nutrition 80.4 (2004): 919-923.
Seldin, Donald W. "Renal handling of calcium." Nephron 81.Suppl. 1 (1999): 2-7.
Jeon, Un Sil. "Kidney and calcium homeostasis." Electrolyte & Blood Pressure 6.2 (2008): 68-76.