Anatomy and Physiology of Children and Adolescents - M. R. Sapin 2007

Endocrine System
Classification, Structure, and Functions of Endocrine Glands
Parathyroid Glands

The Parathyroid glands are round, pea-sized Organs, four in number, located on the posterior surface of the thyroid lobes, two on each lobe. The total mass of these glands in an adult is about 0.5 g. The glandular Cells, or parathyroid cells, produce parathyroid hormone (PTH), which regulates Blood Calcium and phosphorus levels, essential for the normal excitability of the nervous and muscular systems and for maintaining bone calcium content.

In humans, hypofunction of the parathyroid glands leads to a decrease in blood calcium and an increase in potassium levels, causing heightened excitability and Muscle spasms. When blood calcium is deficient, it is leached from the bones, causing them to become flexible and soft. Conversely, Hyperfunction of the parathyroid glands results in calcium deposition in the walls of Blood Vessels and the Kidneys.



Last update: 10/08/2026

Editorial and Educational Adaptation: This material has been compiled based on the primary/original source text. The project team performed an editorial review, corrected technical inaccuracies, structured sections, and adapted the content for an educational format.

What was processed:

  • elimination of formatting defects (OCR errors, structural breaks, corrupted characters);
  • editorial organization of content;
  • standardization of terminology in accordance with academic sources;
  • verification of factual statements against the original source text.

All mentions of the author, publication year, and origin of the primary text have been preserved in accordance with the source.