Scenario: Calcium is an important element that serves many functions in the human body. Calcium is stored in our bones. Like sugar and our metabolism, calcium levels need to be regulated. Two hormones have been found to support calcium regulation: calcitonin and parathyroid hormone. Calcitonin decreases blood calcium levels while parathyroid hormone increases calcium levels. Based on your knowledge of biology, hypothesize how these two hormones regulate blood calcium levels. Include specific observations that should be made to support your hypothesized mechanism of control.

Please note:
Calcitonin is released from the thyroid.
Parathyroid hormone is released by the parathyroid glands.