Māris kļaviņŠ, azamat azizov, JĀnis zaļoksnis environment, pollution, development: the case of uzbekistan

 6.3.3.  Effects of environmental pollutants on the endocrine 
system
The endocrine system is composed of internal secretion glands, 
regulating many body functions through the hormones synthesised 
in  these  glands  (Figure 6.9).  Female  organisms  produce  estrogenic 
hor mones,  whereas  male  organisms  –  androgenic  hormones.  The 
endocrine glands of the human body are the thyroid gland, para-
thyroid glands, the thymus, gonads, the adrenal gland and pancreas. 
The placenta, kidneys, the liver, fat tissue and the endothelium also 
have endocrine secretion functions.
Hormones  are  specific  substances  that  are  synthesised  in 
different  tissue  cells  (endocrine  gland  cells)  and  released  from 
there into the intercellular solution, spreading through (or with) 
this solution and regulating target cell functions and processes 
throughout the body.

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ENVIRONMENT, POLLUTION, DEVELOPMENT:  THE CASE OF UZBEKISTAN
Hypothalamus
Hypophysis
Epiphysis
Parathyroid glands
Thyroid gland
Thymus
Adrenal gland
Prostate
Ovaries
Hormones regulate the body’s development and growth; they 
influence behaviour, regulate the reproductive cycle (the menstrual 
cycle, onset and progress of pregnancy) and significantly affect the 
functioning of the body (the functioning of skeletal, circulatory and 
immune systems as well as brain performance). Typical examples of 
reproductive hormones are estradiol, estrone and estriol.
There also are many substances whose structure and properties 
are similar to those substances that may actively affect the functi-
oning  of  the  endocrine  system.  Such  substances  may  affect  orga-
nisms in embryonic or foetal development stages as well as the 
re productive system, central nervous system, immune system and 
endocrine  regulatory  processes.  A  typical  characteristic  feature  of 
such substances is that their effects are initiated by low con centra-
tions and may become manifest only in future generations. Just as 
carcinogenic  substances,  the  substances  affecting  the  endo crine 
system do not belong to one particular group of substances; the 
effects come about as a result of the action of various structurally 
different substances.
The  most  widely  studied  group  of  substances  affecting  the 
endocrine system are environ mental estrogens or exoestrogens.