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НазваImpact of evolution on human thought Testosterone (реферат)
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РозділІноземна мова, реферати англійською, німецькою
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Farid Gazizov

 

Impact of evolution on human thought

 

Testosterone

 

For a long period of time humans could not answer the question of what

makes a man, a man, and a women, a women. As was recently found main

difference is not just in presence of genitals. Probably one will ask

why? The answer is that genitals themselves are indirect products of

another matter. The name of this matter is testosterone.

 

“Testosterone is a hormone that stimulates sexual development in male

human beings. It belongs to a family of hormones called androgens.

Primarily the testicles, a part of male sex glands, produce androgens.

The ovaries in females and the adrenal glands in both sexes also yield

small amounts of testosterone and other androgens (The world book

encyclopedia).”

 

In its earliest crucial functions, in developing embryo, testosterone

play the key role in telling the cells of the genetically male embryo to

develop as a male. It is amazing, but all human embryo begins as

females for the first few weeks of an embryo’s life, a small group of

cells have potential to develop either as ovaries or testes. About one

million of genes that are needed to direct the development of a human

being, one single gene (the “SRY” gene), which is carried on the Y

chromosome, is responsible for determining the sex of the embryo. If

the embryo’s cells contain the “SRY” gene, the embryo will develop

testes, which at some point and for a limited period of time early in

its development produce and release a big amount of testosterone. It

turn, testosterone then signal the cells of other parts of the embryo to

develop as a male.

 

As shown in the study by a Stanford research group namely testosterone

is responsible for formation of genitals. An experiment was held on

newborn female rats. They were injected with testosterone.

Surprisingly, but the female rats developed male genitals, and female

genitals began disappearing. Later “converted” female rats started

revealing purely male behavior, and they were fully aware of usage of

their “new” male genitals. The same experiment was performed with male

newborn rats. It is amazing, but their penises withered and later

completely disappeared. This experiment is not ethical to perform on

humans, but random facts suggest that all most the same can be done with

humans. For instance, in lesbian couple, butches (female that

represents male) use testosterone injections to develop male features

such as deep voice, facial hair and muscles (“The He Hormone,” Andrew

Syllivan)

 

In girls, the adrenal glands begin to produce testosterone earlier than

in boys. That’s is how and why girls mature earlier, as a rule, than

boys. It was testosterone that stimulated the growth of girls pubic

hair and underarm hair (there are testosterone receptors in the skin of

the pubic area and the skin of the underarm that are genetically

programmed to react to testosterone by producing hair). And

testosterone stimulated girls skin to produce more oil, contributing to

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