kõrvalkilpnäärmed

Kõrvalkilpnäärmed, also known as parathyroid glands, are small endocrine glands typically located behind the thyroid gland in the neck. Most people have four parathyroid glands, two on each side, though variations in number and location can occur. These glands are crucial for regulating calcium levels in the blood and within the body.

The primary hormone produced by the parathyroid glands is parathyroid hormone (PTH). PTH plays a vital role in maintaining calcium homeostasis. When blood calcium levels drop too low, the parathyroid glands release PTH. This hormone then acts on several targets to increase calcium levels. It stimulates the bones to release stored calcium into the bloodstream. It also promotes the reabsorption of calcium by the kidneys, reducing its loss in urine. Additionally, PTH influences the intestines to absorb more calcium from food, although this effect is indirectly mediated through vitamin D activation.

Dysfunction of the parathyroid glands can lead to significant health problems. Hyperparathyroidism occurs when the glands produce too much PTH, leading to elevated blood calcium levels (hypercalcemia). This can cause symptoms such as fatigue, bone pain, kidney stones, and cognitive disturbances. Hypoparathyroidism, conversely, occurs when the glands produce too little PTH, resulting in low blood calcium levels (hypocalcemia). This can manifest as muscle cramps, spasms, tingling sensations, and in severe cases, seizures. The proper functioning of the parathyroid glands is essential for maintaining bone health and the normal functioning of nerves and muscles.