Parathyroid Hormone: Essential for Calcium Balance
Calcium is one of the most important minerals in the human body. It is necessary for the proper functioning of various systems, including the nervous, muscular, and skeletal systems. However, maintaining calcium balance can be challenging for the body, and it requires the involvement of several hormones, including the parathyroid hormone. In this article, we will discuss the functions of the parathyroid hormone, how it regulates calcium levels, and the various factors that affect its secretion.
What is Parathyroid Hormone?
The parathyroid hormone (PTH) is a hormone produced by the parathyroid glands, which are small glands located in the neck, behind the thyroid gland. The parathyroid glands produce four small glands, two on each side of the thyroid gland. PTH is an 84 amino acid polypeptide hormone that plays a crucial role in regulating calcium levels in the body.
How does Parathyroid Hormone Regulate Calcium Level?
The parathyroid hormone regulates calcium levels in the body through its effects on the bones, kidneys, and intestines. When blood calcium levels are low, the parathyroid glands secrete PTH, which stimulates the release of calcium from the bones into the bloodstream. PTH also promotes the absorption of calcium from the intestines into the bloodstream and decreases the excretion of calcium from the kidneys.
How Does Parathyroid Hormone Affect Bones?
The parathyroid hormone is crucial for the maintenance of bone health. Low levels of PTH result in decreased bone density and increased risk of fractures. On the other hand, high levels of PTH can lead to bone resorption, which involves the breakdown of bone tissue and the release of calcium into the bloodstream. Over time, this can lead to weakened bones and increased risk of fractures.
How Does Parathyroid Hormone Affect Kidneys?
The parathyroid hormone also plays a critical role in the regulation of calcium levels in the kidneys. PTH increases the reabsorption of calcium in the kidneys, preventing excessive loss of calcium in the urine. It also promotes the conversion of vitamin D into its active form, which enhances the absorption of calcium from the intestines.
What Factors Affect the Production of Parathyroid Hormone?
Several factors can influence the secretion of the parathyroid hormone, including blood calcium levels, vitamin D levels, and phosphate levels. Low blood calcium levels increase the production and secretion of PTH, while high calcium levels have the opposite effect. Vitamin D is necessary for the production of PTH, and low levels of vitamin D can lead to decreased PTH production. High phosphate levels can also decrease the production of PTH.
What are the Symptoms of Parathyroid Hormone Deficiency?
Deficiency of the parathyroid hormone, known as hypoparathyroidism, can lead to low blood calcium levels, which can cause a variety of symptoms. These symptoms include muscle cramps, spasms, and numbness, as well as tingling sensations in the hands and feet. Hypoparathyroidism can also cause seizures, cataracts, and dental abnormalities.
What are the Symptoms of Parathyroid Hormone Excess?
Excess of the parathyroid hormone, known as hyperparathyroidism, can result in high blood calcium levels, which can lead to a range of symptoms. These symptoms include fatigue, muscle weakness, loss of appetite, nausea, vomiting, and constipation. Hyperparathyroidism can also cause bone pain, kidney stones, and osteoporosis.
How is Parathyroid Hormone Measured?
The parathyroid hormone can be measured in the blood using a PTH test. This test measures the level of PTH in the blood, which can provide insights into the functioning of the parathyroid glands and the regulation of calcium levels.
The parathyroid hormone is a critical hormone that plays a vital role in the regulation of calcium levels in the body. It stimulates the release of calcium from the bones, promotes calcium absorption from the intestines, and increases calcium reabsorption in the kidneys. Several factors can influence its secretion, and its deficiency or excess can lead to a range of symptoms and complications.
- “Parathyroid Hormone – an Overview.” ScienceDirect Topics, Elsevier, 2021
- “Parathyroid Hormone.” Hormone Health Network, 2021
- “Parathyroid Hormone (PTH) Test.” WebMD, 2021
Common Questions and Answers:
- Q. Which hormones are produced by the parathyroid gland?
A. The parathyroid gland produces one hormone – parathyroid hormone (PTH).