Testosterone
Testosterone is a steroid hormone that is primarily secreted from the testes of males and the ovaries of females. It is the principal male sex hormone and an anabolic steroid.
The average adult male human body produces about 40 to 60 times more testosterone than an adult human female body. Females, however, are more sensitive to the hormone than men. Too high doses of testosterone in women can cause baldness, facial hair, acne or deepening of the voice. High levels of testosterone for men, however, can promote good health as they lower the risks of high blood pressure and heart attack.
Testosterone plays a major role in the health and well-being of men. As a dug, it works in preventing osteoporosis and may be given to treat certain medical conditions such as hypogonadism (low gonadal function) and cryptorchism (no descent of the testis into the scrotum).
How does it affect the brain formation?
Testosterone affects the entire body, including the brain. Since the testosterone levels in males are larger than that of females, the male human brain tends to grow larger in fetuses.
How does it affect behavior?
Aggressive behavior has been associated with hypogonadism, a symptom of very low testosterone levels in the male body. It appears that that the combination of supra-physiological and low levels of testosterone manifested in hypogonadism cause mood disorders and aggressive behavior in men. Evidence also suggests that low testosterone levels may be a risk factor for cognitive decline which may be the cause for an Alzheimer’s type of dementia in older men.
How does it affect sperm development?
Testosterone is the most important hormone involved in controlling sperm production. Although it is not directly responsible for manufacturing sperm cells, it its role in the production process will dictate the amount of sperms the testis is to be produced. When testosterone levels drop in the body, a sequence of triggers tells the testis to produce more testosterone and more sperm.
General Functions of Testosterone in the Body
- Regulates acute HPA response under dominance challenge
- Affects libido and penile erection frequency
- Under dominance challenge, may play a role in the regulation of the fight-or-flight response
- For mental and physical energy
- For maintenance of muscle tropism
- Decreases visceral fat mass, decreases total cholesterol, and glycemic control
Factors that decrease testosterone levels
There are a number of factors that decrease testosterone production. They include side testicular dysfunction, drug dependence and the elevation in the adrenal hormone cortisol. Testicular dysfunction may also results from damaged testicles. Congenital problems such as decreased amount of male hormones and rare malformation syndromes can also result in low testosterone production. Acquired problems such as chronic illness, starvation, head trauma, surgeries, cancers, infections, and alcoholism are also among the causes of low testosterone levels.
Aging is the biggest contributor to low testosterone levels in body. As men grow older, a number of changes occur that reduce the testosterone level in their bodies. This event, which alters the ratio between testosterone and the chief female hormone, estrogen is referred to as partial androgen deficiency.
One very important factor that affects the level of testosterone is an enzyme called aromatase. Aromatase is an enzyme found in fat tissues. It is the enzyme that is responsible for converting testosterone into estrogen. Men who have excessive body fat are most likely to store more of the enzyme aromates. The more aromates there are in the system, the more testosterones will be converted into estrogens and will result to the alteration of the ratio for both hormones. In cases were the testosterone levels are low, the weight problem is worsened. Low testosterone causes obesity; the lower the testosterone level, the more fat is stored by the body. And because there is more body fat, more aromates are produced, which in turn deplete the levels of testosterone further. This relationship between low testosterone and obesity is described as the hypogonadism or the obesity cycle.
Diabetes milletus is known to be one factor that can significant decrease the levels of testosterone. Intake of drugs like glucocorticoids, used in the treatment of acute allergic disorders, ketoconazole, used in the treatment of skin infections and a deficiency of zinc in diet, have been known to indirectly cause a decrease in testosterone.
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