Paratüreoidnäärmed

Paratüreoidnäärmed, also known as parathyroid glands, are four small endocrine glands located in the neck, usually embedded in the posterior surface of the thyroid gland. Their primary function is to produce and secrete parathyroid hormone (PTH). PTH plays a crucial role in regulating calcium and phosphate levels in the bloodstream. It achieves this by acting on several target organs, including the bones, kidneys, and intestines.

In the bones, PTH stimulates osteoclasts to resorb bone tissue, releasing calcium into the circulation. In the kidneys, PTH increases the reabsorption of calcium from the filtrate back into the bloodstream and promotes the excretion of phosphate. It also stimulates the conversion of vitamin D to its active form, calcitriol, which then enhances calcium absorption from the intestines.

Disruptions in parathyroid gland function can lead to significant health issues. Hypoparathyroidism, a condition of insufficient PTH production, results in low blood calcium levels (hypocalcemia), which can cause muscle cramps, spasms, and even seizures. Conversely, hyperparathyroidism, characterized by excessive PTH secretion, leads to high blood calcium levels (hypercalcemia). This can manifest as kidney stones, bone pain, fatigue, and cognitive problems. The intricate balance maintained by paratüreoidnäärmed is essential for numerous physiological processes.