The thyroid gland (thyroid gland, thyroid gland) consists of two parts (lobes), covering the trachea and connected by a thin isthmus, which is located at the level of the 2nd-3rd ring of the trachea under the larynx. In its form, the thyroid gland resembles a shield or butterfly, with the lower parts of its lobes wide and short, and the upper ones, on the contrary, narrow, high and slightly divergent. In some cases (30-35%), its additional so-called “pyramidal” part is found. The location of the thyroid gland does not depend on gender, that is, where it is located in men, in the same place it is found in women.
The size and weight of the thyroid gland is individual. The average weight of the thyroid gland of an adult varies from 12 to 25 grams, and the size varies between 2.5-4 cm (relative to length), 1.52 cm (relative to width), and 1-1.5 cm (relative to thickness). The normal volume of the thyroid gland in men is up to 25 ml, and in women up to – 18 ml (fluctuations in volume associated with the menstrual cycle are possible).
What is the thyroid responsible for?
According to medical Wikipedia, the thyroid gland is one of the most significant endocrine glands characteristic for vertebrate organisms (including humans), whose function is to store iodine and generate iodine-containing hormones (iodothyronines), which take an active part in regulating the multitude of metabolic processes of substances passing both in individual cells , and in the body as a whole.
Thyroid hormones produced by the thyroid gland are represented by thyroxine (T4, tetraiodothyronine), triiodothyronine (T3) and thyrocalcitonin (calcitonin).
Synthesis of thyroxine and triiodothyronine is carried out in thyrocytes, which are epithelial follicular cells (follicles) of thyroid gland and are associated with iodine. These hormones control the processes of normal maturation and growth of various organs and tissues (including the CNS), as well as metabolic processes of energy and substances. They also enhance protein synthesis and the formation of erythrocytes, increase gluconeogenesis (the release of glucose from fats and proteins) and increase the breakdown of fats. From their level depends the concentration of sex hormones and, as a consequence, full sexual development.
Isolation of the peptide hormone of thyrocalcitonin occurs due to the C-cells (parafollicular cells) of the thyroid gland. This hormone takes an active part in the regulation of cellular processes of calcium and phosphorus metabolism, thanks to which normal growth and further development of the human bone apparatus becomes possible. When bone wears or bone integrity disorders, calcitonin compensates for their wear, by embedding calcium and phosphates in the bone tissue, prevents the formation of osteoclasts (bone destruction factors), stimulates the multiplication and functional activity of osteoblasts, thereby leading to the fastest formation of new bone tissue.