The thymus gland and its physiology
Endocrinology / / April 30, 2016
F iziologiya thymus
Until now, the question of the thymus gland physiology in general, its endocrine function in particular is unclear.Numerous observations of direct action animal glands, introducing organ extracts and particularly the study of the effects of thymectomy in animals of different ages were given reason to believe that the thymus is the organ that develops its activities mainly in the growing season.This position finds confirmation in the age of the thymus gland morphology features.When you remove the thymus gland in puppies, pigs, rats, and other animals in the first weeks of their life comes quite naturally stunted compared to the control animals, and changes in the skeleton (bones, especially tubular, become thin, soft, exposed to the curvature).In contrast, transplantation of the thymus gland, or feeding her animals leads to the acceleration of growth and the processes of bone ossification.In adult animals, or complete extirpation of the thymus or its extracts administration
Numerous attempts to isolate the hormone of the thymus are still unsuccessful.True, Bomskov and Sladovic received from the thymus gland lipoid extract containing allegedly hormone that causes a decrease in glycogen in the liver and the heart of the experimental animal and the rise in blood sugar.
These data were confirmed and further developed by many scientists.They found that the lipoid thymus extract contains at least four fractions having different chemical composition and having unequal effect on the metabolism.The fraction containing mainly sterols, reduce glycogen content in the liver, while the fraction consisting essentially of fosfotidov increases its contents.
After partial resection of the thymus gland in animals its remnants, according to many researchers, are not subject to compensatory hyperplasia.Therefore, it should be recognized that the thymus gland does not meet the classical criteria of an endocrine organ.
However, there is a lot of circumstantial evidence giving grounds to assume the existence of endocrine function of thymus:
1. The thymus develops from the same embryonic rudiments that typical endocrine glands (thyroid and parathyroid).
2. Histological and histochemical thymus structure although it has similarities to lymphoid tissue, but differs from the latter lack lymph follicles, and significantly greater than in the lymphoid organs, nucleoproteins content, particularly deoxyribonucleic acid.
3. The epithelial cells and corpuscles gassalevyh histologically demonstrated the presence of secretory activity.
4. During hibernation in animals observed involution not only typical of the endocrine glands (thyroid, adrenal glands, gonads), and thymus.
5. The thymus gland, along with other endocrine organs, actively involved in the reactions of the organism to "stress".
- Diseases of the thymus (thymus) gland
- Physiology of the adrenal cortex
- Syndrome Cushing - Cushing
- diagnosis and course of the syndrome Cushing's
- Treatment syndrome Cushing's
- androgen-producingtumors of the adrenal cortex
- Biological effects of catecholamines
- diagnosis and treatment of pheochromocytomas
- Diseases of the adrenal medulla
- treatment of chronic adrenal insufficiency
- congenital (inborn) hyperaldosteronism
- congenital virilizing adrenal hyperplasia
- treatment of congenital adrenal hyperplasia
- Acute failure of the adrenal cortex
These provisions give reason to believe the thymus gland kind of body with certain, yet insufficient elucidation of significance for the normal functioning of the body.Apparently, the greatest physiological role iron plays in the growing organism, especially in the conditions when the body is exposed to highly damaging factors external and internal environment.