Image by pikisuperstar on Freepik
The Effects of Testosterone on the Body
Testosterone is the single most important hormone responsible for growing male features. Women also have this hormone but is very small and is not necessary for primary female characteristics.
In this post, we want to examine the features of this hormone and the differences this hormone causes between the sexes.
The Human body
From the first trimester of intrauterine life, the human male fetus begins to secrete testosterone. During adolescence, the male levels of this hormone reach the highest rate of secretion and typically these levels stay stable until the person reaches the age of 30. After this age, the levels of testosterone begin to decrease in most men.
In women, the function of testosterone is more for repair, growth, and bone density. The size of the breast can also be smaller.
When men produce testosterone in inadequate amounts, it leads to a disease known as hypogonadism. This typically will require hormone replacement therapy prescribed by an endocrinologist.
When men do not have enough testosterone a lot goes wrong, with their reproductive system. The effects are also thought to affect brain function as reflected in behavioural changes.
Endocrine
This is the system of messaging in the body that utilizes hormones secreted by glands. There are different systems in the body and all of them have receptors that are responsive to endocrine glands. The gland of all glands is the pituitary gland and it is located in the brain. This gland receives information from the hypothalamus about the number of hormones that is available in the blood and is responsible for regulating other glands.
The pituitary gland secretes hormones give instructions to the testicles on whether to increase or reduce testosterone secretion. For women, it’s the adrenal glands and the ovaries that produce the minute amounts of testosterone.
The secretion of testosterone begins and is sustained from pregnancy until about 15 years. Throughout this time, it is expected to be equal to or higher than the levels seen in females of the same age.
From the age of 15, the levels are exponentially higher than what is seen in females.
If a boy does not get the right concentration of testosterone, the boy may not have a high-pitched voice and have a little body hait. The muscle mass of boys along with their sex drive will also be remarkably affected.
After this peak in adolescence, the concentration usually stays relatively the same before dropping by 1% every year.
Reproduction
In the first trimester of pregnancy, the fetus starts forming genitalia under the influence of testosterone. At puberty when there is a surge in the testosterone level it leads to an increase in the growth of the penis and testicles. The levels stay high and lead to increased sperm production.
When a man has low levels of testosterone it can lead to erectile problems. Other reproductive organs are also smaller than they ought to be.
In congenital adrenal hyperplasia, testosterone concentration is increased during a female pregnancy. This leads to infertility, an enlarged clitoris, acne and other masculine features.
Sexual behaviour
The testosterone levels in adolescence cause genital growth and the growth of pubic hair. The secondary feature such as muscle development, voice changes and male hair growth takes place.
As these changes take place males start having more interest in sex.
The disuse theory holds in males that if there are low levels of testosterone they do not develop a normal sex drive. Sexual activity also causes increased testosterone levels and there might be a significant drop in testosterone levels going through a period without sexual activities.
The Brain
The hormones in the body circulate to every organ in the body including the brain through the circulatory system. The regulation of testosterone takes place in the brain through the efforts of the hypothalamus and the pituitary glands. Testosterone is related to aggressiveness and dominant behaviour. It is also responsible for the comparatively competitive behaviour of males.
Males are also noted to have less competitive behaviour when testosterone is less than a certain level and they also have lowered self-esteem.
It is also believed to make men go through low moods and have issues with paying attention. Other factors are involved with personality but testosterone plays an important role.
Skin and Hair
Testosterone causes hair growth in the armpits, the pubic region and the face. There may be general hair growth on the limbs and chest. When a man losses testosterone, there may be a loss of body hair.
Muscle and Connective tissue
The bones are connective tissue and in general, they are dense around the body. Because of testosterone connective tissue in general have more resilience.
Among the connective tissue, the blood cells are more concentrated in the blood and the bones grow stronger.
Testosterone also increases the basal metabolic rate and this increases fat burning in males.
Circulatory System
Testosterone has been noted to have effects on the heart, by recurring cholesterol and destroying blood clothes thereby preventing heart disease.
More study is being done to assess if testosterone is a viable form of therapy for heart conditions.