In connection with the development of general physiology and endocrinology, it became known that the body of higher animals and humans there is not one en dokrinnaya system – the hypothalamus – pituitary, peripheral special nye glands (thyroid, pancreas, parathyroid, adrenal glands, ovaries and testes), but also three more systems – tissue, autocrine and paracrine .
1. Tissue system. In parenhi IU of all organs and tissues vyrabaty vayutsya hormones, some of which are today investigated satisfactorily, the other part – is not enough. Tissue Vym hormones are hormones produced myocardium predser diy, which has the property to promote natriuresis , reduce contains zhanie natrium in the blood and arteries cial pressure. Perhaps, this hormone has yet others their properties.
Pancreas ne chenyu, muscles, glands zhelu zling tract vyrabaty INDICATES somatostatin , somatomedin , and others. Hormones. The first of these, somatostatin , blocks dei Corollary growth hormone , pituitary and other hormones (AKTT, TSH), and the second, somatomedin , contributes to the implementation of the action somatotro pin . In the salivary glands, in addition to saliva, an epidermal growth factor is also produced .
2. Autocrine hormonal system.
This system includes all the cells that produce hormones for themselves. Autocrine secretion of hormones is also characteristic of embryonic cell types, and with tumor cell degeneration, in which the restriction of cell self- division is eliminated .
Normally, some embryonic cells produce a growth factor that acts on the adjacent roll stands ki, under the influence of which the latter de divisible. Later during the growth of op -organisms by these dividing cells still refer to the information on termination growth factor production. Such a balanced state of preservation etsya life. And at Sports Corollary to carcinogens or tissue injury factor production growth resumes torus. In cases Rep wounds it stops as wound healing, and for development of malignancy continues growth factor, which leads to the fact NIJ cells and tumor growth. Finite but this autocrine -gormonalny mechanism of tumor development has not mo nopolny, it involves a number of other factors. The growth factor is secreted by platelets, which contributes to wound healing, vascular growth.
3. The paracrine “endocrine” system is the most economical.
Produced paracrine millstands kami or a group of cells “iron mi” hormones affect near underlying tissue cells. These hormones are often no common values Niya and need mainly to neighboring cells. In this case, the body acts sparingly – it produces hormones in small quantities in those areas where they are needed.
Examples paracrine secretion is the secretion of neurotransmitters acetylcholine, cholinesterase , re give one her arousal from Rhone to another or muscles. Crate ki (calf) APUD gastrointestinal system also receives a similar manner ho cha and part of hormones produced Mykh this system ( cholecystokinin , gastrin , bombesin , etc.) Received is in the bloodstream.
The endocrine system of man and the higher animals – very Shiro some concept and it is involved in all physiological processes are organized ma (almost without exception). Although in recent years the endocrine system ma be divided into four groups, it remains the most dominant neuroendocrine system, which in a certain extent subordinated TKA nevaya, autocrine and paracrine endocrine system, in spite of their autonomy.