calcitonin

(noun)

A hormone that is produced primarily by the parafollicular cells of the thyroid. It acts to reduce blood calcium (Ca2+), opposing the effects of parathyroid hormone.

Related Terms

Examples of calcitonin in the following topics:

  • Action of Thyroid Hormones

    • The primary function of the thyroid is to produce the hormones triiodothyronine (T3), thyroxine (T4), and calcitonin.
    • Calcitonin is another hormone released by the thyroid gland that is responsible for modulating blood calcium levels in conjunction with parathyroid hormone, which is released from the parathyroid.

  • Bone and Calcium Homeostasis

    • Calcitonin stimulates incorporation of calcium in bone.
    • When blood calcium concentration rises, the parafollicular cells of the thyroid gland increase calcitonin secretion into the blood.
    • The resulting high levels of calcitonin in the blood stimulate the bone to remove calcium from the blood plasma and deposit it as bone.
    • When the blood calcium level is too low, calcitonin secretion is inhibited and PTH secretion is stimulated.

  • Parathyroid Hormone

    • PTH works in concert with another hormone, calcitonin, that is produced by the thyroid to maintain calcium homoeostasis.
    • Parathyroid hormone acts to increase blood calcium levels, while calcitonin acts to decrease blood calcium levels.
    • This interaction between parathyroid hormone and calcitonin is also an important part of bone remodeling.

  • Overview of the Parathyroid Glands

    • PTH has effects antagonistic to those of calcitonin by increasing blood calcium levels by stimulating osteoclasts to break down bone and release calcium.

  • Overview of Endocrine Glands

    • The thyroid also produces and releases the hormone calcitonin (thyrocalcitonin) that contributes to the regulation of blood calcium levels.
    • Thyrocalcitonin or calcitonin decreases the concentration of calcium in the blood, where most of it is stored in the bones.
    • Calcitonin, a hormone produced by the thyroid gland that also regulates ECF calcium levels, serves to counteract the calcium-producing effects of PTH.

  • Overview of the Thyroid Gland

    • The thyroid also produces calcitonin, which plays a role in calcium homeostasis.

  • Paget's Disease

    • Although there is no cure for Paget's disease, medications (bisphosphonates and calcitonin) can help control the disorder and lessen pain and other symptoms.

  • Development of the Endocrine System

    • The thyroid also produces and releases the hormone calcitonin (thyrocalcitonin), which contributes to the regulation of blood calcium levels.