Testosterone: Discussing the Biological Effects of a Vital Male Hormone

Ball and Stick Structure of Testosterone; Sourced from Pixabay

When you take a look at both sexes in humans and other animals, identifying distinct features that differentiate them isn’t much of a task. For humans, Testosterone is the most important sex hormone found in men. Most people assume that men filled with ego and those who enjoy taking risks, etc. are like that because of high levels of Testosterone in these men, giviing the hormone quite a reputation. This gives a reason for us to actually understand what this hormone is all about. So do read on and enjoy.

Testosterone truly is responsible for the development of certain male characteristics found in humans. You’d be surprised to know that it even affects the hair patterns on the human head, muscles, beard growth and the overall personality of a male human. And there is definitely more to this particular hormone than most people think.

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So how is this Hormone produced?

In a general sense, Hormones that give men the male characteristics are called Androgens and the most important of these Androgens happens to be Testosterone. Most of the testosterone is actually produced in the Testes; however a little amount is produced in the Adrenal Cortex. They are specifically produced from the Leydig Cells.

Clusters of Leydig Cells; By Author:Nephron; Sourced from Wikimedia Commons Under License

Over the years as the male child grows, the level of testosterone increases and rises at a dramatic rate. The boom is well seen during the puberty stage of growth and development. And after puberty, the testosterone levels remain on the high side.

An average man has 8-12 nmol/L of testosterone and if it happens to be below this range, that simply signifies a deficiency. However, the respective amount found in each man is also dependent on genetics. For women, the level is much lower (about 5% of the amount found in men) and the hormone is actually used to synthesize the important female sex hormone: Estrogen. To enable this synthesis, an enzyme named Aromatase is essential and can be found in cells and many parts of the body such as the brain, Adrenal glands, testes and ovaries.

The production process of testosterone in the testicles actually kicks off in the brain. The hypothalamus is the starting point and regulation point since it links the body’s Nervous System to the Endocrine system through the Pituitary gland.

How LH and FSH are released and their functions; By Author:[Open Stax College]; Sourced from Wikimedia Commons Under License

The Pituitary Gland has two sections of which the anterior section produces two vital hormones i.e. LH and FSH. The former is responsible for stimulating the production of Testosterone in the testes while the latter is involved in the production of Sperm. As additional functions, LH (Luteinizing Hormone) and FSH (follicle-stimulating hormone) report back to the brain and inform the body whether it is producing enough Testosterone and Sperm while the brain finds a balance for each.

For researchers who work on testosterone and understand how it affects human behavior, samples are collected from various body fluids such as the Saliva, Blood and Urine. This is because testosterone is a fat soluble hormone and it can pass through cell membranes, bind effectively with hormone receptors and bring about certain changes in the cell structure.

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What then is the Impact of this Hormone on Humans

In an amazing way, for men who have fertility issues, a strategy of using injections of gonadotropin hormones was devised. The gonadotropins comprise LH and FSH which opens a window for the men to produce both testosterone and fertile sperm. The sperm can then be collected, frozen and stored for use later in the future.

Testosterone in males and Estradiol in females have been shown to contribute significantly to human bone strength and density right from gestation to maturity. This can be seen during the first three months of pregnancy, as Testosterone causes the ring finger to grow longer than the index finger in male fetuses. Studies have shown that in females, the index fingers are usually longer than the ring fingers, which is not the case in men! Sounds quite interesting, right?

Typical Male finger digits, where the Index finger is shorter than the Ring finger due to longer exposure to Testosterone during gestation period; Sourced from Wikimedia Commons Public Domain

Another study showed that the male fetus is exposed to more testosterone in the amniotic fluid of the womb than the female fetus. During the early stages of pregnancy, there really isn’t much to differentiate the gender of a foetus since the genitalia seem to look alike. However, after the 7th week of gestation, a gene present in the Y chromosome gets activated and results in the development of testicles. Later on, testosterone comes into action and plays a role in developing masculine characteristics in many parts of the male foetus in which the brain is not left out.

A 10 weeks human Fetus srrounded by Amniotic fluid in Amniotic Sac ; By Author:drsuparna; Sourced from Wikimedia Commons Under License

This goes to show that Testosterone also has an effect on brain development! A study on children born with different levels of fetal testosterone exposures showed that those with lower levels (most generally girls) sought eye contact more actively and had better verbal skills when compared to boys. The tests carried out by the team confirmed that girls actually had better social and verbal skills than boys. However, the researchers also found out that the boys under study had better analytical skills. There are claims that there is a relationship between the exposure to testosterone and the higher rate of autism in boys when compared to girls.

Moving away from kids, quite a number of adult men are currently on Testosterone replacement therapy to treat exhaustion, depression and other health cases. The Pharmaceutical companies and the health sector at large, make millions of dollars from the sales of Testosterone preparations.

However, It is rather being suggested that testosterone levels drop in men who tend to be obese/overweight, due to the high level of visceral fat in their abdominal cavities. The excess visceral fat sometimes causes insulin resistance, lower testosterone levels and even high blood pressure.

Lastly, the most popular use of Testosterone in youths involves doping in competitive sports. The compound actually plays a vital role in regulating body mass and how the body is affected by exercise. When we exercise for a long period of time, the muscles are a bit damaged. And when we get to rest, the muscles get repaired and increase in size and strength.

Capsules of Various Anabolic Steroids; Sourced from Wikimedia Commons Public Domain

Anabolic Steroids are derivatives of Testosterones and are widely used in the fitness world by both professional athletes and Amateur athletes. The anabolic steroids help to increase the amount of testosterone in the body needed by body builders since the amount of testosterone produced in the body will not be enough. This poses a problem as many people actually abuse these substances with people consuming over 1000mg of these steroids daily. When you compare this amount to that of testosterone produced naturally in the body (which is around 4-8mg), you get to see the problem here.

The side effects attached to the abuse of Anabolic Steroids can be quite dangerous, leading to strokes, high blood pressure, heart attacks and even liver damage. An excessive intake of testosterone can also lead to a decline in sperm production. This is because the brain receives the signal that there is enough testosterone in the body, there by cutting off the supply.

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We can conclude on the note that testosterone is what makes men who they are, and all men need a minimum amount to be balanced physically and socially. Social and cultural environment factors also play a role in how testosterone affects a man’s behavior. There is a whole lot to digest when it comes to Hormones. You can check out some of my reference article to get a much better understanding.

Thanks for reading through guys. I look forward to your comments and suggestions.

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REFERENCES

Testosterone, mood, behaviour and quality of life
The role of testosterone in social interaction
Fetal Testosterone Predicts Sexually Differentiated Childhood Behavior in Girls and in Boys
Topical Review: Fetal Testosterone and Sex Differences in Typical Social Development and in Autism
Testosterone

AS COMPOSED BY QUE