Parathormone

Parathormone (also known as Parathyroid hormone or PTH) is a hormone secreted by the parathyroid glands in the neck. It plays a crucial role in maintaining the body's calcium and phosphorus levels.

Function

Parathormone increases the concentration of calcium in the blood by stimulating the release of calcium from the bones, increasing the absorption of calcium in the intestine, and increasing the reabsorption of calcium in the kidneys. It also stimulates the production of active vitamin D in the kidneys, which further increases the absorption of calcium in the intestines.

Regulation

The secretion of parathormone is regulated by the concentration of calcium in the blood. When the blood calcium level is low, the parathyroid glands secrete more parathormone. When the blood calcium level is high, the parathyroid glands secrete less parathormone.

Clinical significance

Abnormal levels of parathormone can lead to several medical conditions. High levels of parathormone can cause hyperparathyroidism, which can result in osteoporosis, kidney stones, and neuropsychiatric disorders. Low levels of parathormone can cause hypoparathyroidism, which can result in tetany, seizures, and arrhythmias.

See also

• Calcitonin
• Vitamin D
• Hypercalcemia
• Hypocalcemia

Parathormone Resources
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References

External links

• Parathormone at PubMed Health
• Overview of Parathyroid Function at Merck Manuals Professional Edition

Further reading

• Parathyroid Hormone at NCBI Bookshelf
• Parathyroid Hormone at Encyclopædia Britannica