Final answer:
Calcitonin decreases reabsorption of calcium in the kidneys leading to increased excretion of calcium in urine, inhibits osteoclast activity and stimulates osteoblasts to lower blood calcium levels.
Step-by-step explanation:
Calcitonin is a hormone produced by the thyroid gland that plays a crucial role in calcium homeostasis. Its release is triggered by high blood levels of calcium. One of the responses induced by calcitonin in the body is to decrease reabsorption of calcium by the kidneys. This hormonal action promotes the excretion of calcium into the urine, subsequently lowering blood calcium levels. It also inhibits the activity of osteoclasts, which are cells responsible for breaking down bone and releasing calcium into the bloodstream. Additionally, calcitonin stimulates osteoblasts, which aid in incorporating calcium into bone tissue, thereby promoting bone formation.