<Table> <Tr> <Td_colspan="4"> View / Edit Human </Td> <Td_colspan="0"> </Td> </Tr> </Table> <Tr> <Td_colspan="4"> View / Edit Human </Td> <Td_colspan="0"> </Td> </Tr> <P> Calcitonin (also known as thyrocalcitonin) is a 32 - amino acid linear polypeptide hormone that is produced in humans primarily by the parafollicular cells (also known as C - cells) of the thyroid gland, and in many other animals in the ultimopharyngeal body . It acts to reduce blood calcium (Ca), opposing the effects of parathyroid hormone (PTH). </P> <P> Calcitonin has been found in fish, reptiles, birds, and mammals . Its importance in humans has not been as well established as its importance in other animals, as its function is usually not significant in the regulation of normal calcium homeostasis . It belongs to the calcitonin - like protein family . </P>

Which cells in the thyroid gland produce calcitonin
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