Parathyroid gland

The parathyroid glands are small endocrine glands in the neck of humans and other tetrapods that produce parathyroid hormone. Humans usually have four parathyroid glands, which are usually located on the rear surface of the thyroid gland, or, in rare cases, within the thyroid gland itself or in the chest. Parathyroid glands control the amount of calcium in the blood and within the bones.

Structure

The parathyroid glands are two pairs of glands usually positioned behind the left and right lobes of the thyroid. They are small, light-colored lumps that stick out from the surface of the thyroid gland. Each gland is covered by a thin capsule of connective tissue, and they are usually located on the posterior surface of the thyroid gland.

Function

The sole function of the parathyroid glands is to regulate the calcium level within the body within a very narrow range so that the nervous and muscular systems can function properly.

Clinical significance

Parathyroid disease is conventionally divided into states where the parathyroid is overactive (hyperparathyroidism), and states where the parathyroid is under- or hypoactive (hypoparathyroidism).

See also

• Endocrine system
• Hyperparathyroidism
• Hypoparathyroidism
• Parathyroid hormone

External links

• Parathyroid gland at parathyroid.com
• Parathyroid Glands at endocrineweb.com

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  Diagram of the parathyroid gland
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  Illustration of thyroid and parathyroid glands
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  Intermediate magnification of parathyroid gland
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  Annotated image of oxyphil and chief cells in parathyroid
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  3D animation still of hyperparathyroidism
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  Annotated gross pathology of parathyroid gland
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  Anatomical illustration of parathyroid gland