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- What are the parathyroid glands?
- Important parathyroid glands facts
- Why parathyroid glands are important
What are the parathyroid glands?
The parathyroid glands are endocrine (or homone-producing) glands that are located at the back of the thryoid gland. There are four parathyroid glands, two one each lobe (left and right) of the thyroid.
The parathyroid glands are very small, they are about the size and shape of a grain of rice.
The parathyroid glands produce a hormone called parathyroid hormone, which regulates the amount of calcium in the blood, to enable the nervous and muscular systems to function properly.
Important parathyroid glands facts
- There are 4 parathyroid glands - 2 on each lobe of the thyroid gland
- The parathyroid glands, while very small need to control much of the calcium levels in the blood
- The parathyroid hormones stimulate the activation of vitamin D3 (calcitrol) into action, to help increase the absorption of calcium, magnesium and phosphate from food eaten
Why the parathyroid glands are important
The parathyroid hormones are very important because they control the levels of calcium in the blood, by sampling the blood passing through them.
When there is a decreased level of calcium in the blood, the parathyroid glands release parathyroid hormone (PTH) to enable the following:
- Destruction of bone tissue and releasing more calcium into the blood
- Increased activation of vitamin D3 (calcitrol) to increase absorption of calcium, magnesium and phospahte
- Decreased excretion of calcium and magnesium
The parathyroid glands can start to produce too much parathyroid hormone which can increase the levels of calcium in the blood too much and cause many health problems. The condition that this refers to is:
- Hyperparathyroidism
references
- Marieb EM, Hoehn K. Human Anatomy & Physiology. 7th edition, 2006. Benjamin Cummings Publishing
- Tortora GJ, Derrickson BH. Principles of Anatomy & Physiology. 11th edition, 2005. Wiley Publishing
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