1. Calcitonin: -Polypeptide type hormone
-Produced by C-cells (aka parafollicular cells) within the thyroid. The thyroid is located

2. -Calcitonin prevents bones from breaking down by inhibiting osteoclasts, it also inhibits kidney tubules which allows calcium to pass out of the body in urine.

3. Negative Feedback:
When calcium levels in the blood rise above the 9-11 mg/100ml level, the thyroid releases calcitonin, which then inhibits osteoclasts, increases bone calcium production, and stimulates osteoblasts to created more bone, which brings the blood calcium levels down.

4. -Human bodies can still maintain relatively normal calcium ion levels without calcitonin. People whose calcitonin levels are changed through changes to the thyroid (hypothyroidism, hyperthyroidism, thyroid cancer) still have normal calcium concentrations. Calcitonin is actually used medically to treat osteoporosis
Lets think of the body’s calcium levels as a big family. Sometimes it’s stable and functional, and sometimes it’s unbalanced and full of drama. There is always that one relative that stirs up the drama, lets call her Penny Hannah Spencer. In addition, there is always one level headed cousin who calms things down when the drama builds up: good ol cousin Cal C. Tonin

5. Sources
Bowen, R. “Calcitonin.” Colorado State. Colorado State University, 11 Oct Web. 11 Feb <
Tucker, Kelli, ed. “Negative Feedback Mechanism of Regulating Blood.” Gateway CC. Gateway Community College, Web. 11 Feb < .