Which gland secretes calcitonin?

The thyroid gland is responsible for the secretion of calcitonin, a hormone that plays a crucial role in calcium homeostasis. Calcitonin works to lower blood calcium levels by inhibiting osteoclast activity in the bones, which decreases the release of calcium from bones into the bloodstream, and by promoting the excretion of calcium in the kidneys. This hormone acts in opposition to parathyroid hormone, which increases blood calcium levels. Understanding the function of calcitonin is essential, particularly in the context of disorders related to calcium imbalance, such as osteoporosis or hypercalcemia. The other glands mentioned, such as the pancreas, adrenal cortex, and adrenal medulla, are involved in different hormonal functions and do not synthesize or secrete calcitonin. Hence, recognizing the specific role of the thyroid gland in calcium regulation highlights its critical endocrine function.