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.
Derangements of this mechanism lead to hypercalcemia or hypocalcemia, both of which can have important consequences for health. In humans, when the blood plasma ionized calcium level rises above its set point, the thyroid gland releases calcitonin, causing the plasma ionized calcium level to return to normal. When it falls below that set point, the parathyroid glands release parathyroid hormone (PTH), causing the plasma calcium level to rise.