Born in Paris to a grocer, Claude Oscar Monet moved at the age of five to Le Havre, a seaside town in northern France. The ocean and rugged coastline of the region had a profound affect on him at an early age, and he would often run away from school to go for walks along the cliffs and beaches.
Parathyroid hormone serves to increase blood concentrations of calcium. Mechanistically, parathyroid hormone preserves blood calcium by several major effects: 1  Stimulates production of the biologically-active form of vitamin D within the kidney.  Facilitates mobilization of calcium and phosphate from bone.
An increase in blood calcium stimulates calcitonin, a hormone synthesized in the thyroid gland. This hormone lowers blood calcium by inhibiting bone resorption. Calcitonin's physiological function as a regulator of blood calcium levels is relatively minor compared to the actions of PTH and calcitriol.