How does a Man get Testosterone?
by Benjamin Bunting BA(Hons) PGCert
Written by Ben Bunting: BA, PGCert. (Sport & Exercise Nutrition) // British Army Physical Training Instructor // S&C Coach.
There are many parts in the body that must work together to ensure testosterone is produced correctly and your body stays healthy. The hypothalamus and pituitary gland are two major parts of the brain that control testosterone production.
The hypothalamus releases a hormone that signals the pituitary gland to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These two hormones reach the testes to trigger spermatogenesis and testosterone production.
The hypothalamus is the part of your brain that controls your endocrine system. It sends signals to your pituitary gland, which releases hormones that affect different parts of your body. The hypothalamus is responsible for regulating your temperature, fluid balance, appetite, and sleep.
Testosterone is the primary sex hormone in men, and it regulates fertility, muscle mass, and red blood cell production. In women, testosterone is produced by the adrenal glands and the ovaries.
In men, testosterone is produced by Leydig cells in the testes and Sertoli cells in the male gonads. These cells respond to LH, which triggers testosterone production.
When a man has an elevated level of testosterone, his hypothalamus tells the pituitary gland to release gonadotrophic substances, such as follicle-stimulating hormone and luteinizing hormone. These hormones promote a number of functions in the testes, including the development of sperm.
These hormones also help maintain your weight, hydration, and blood pressure. The hypothalamus also keeps your internal temperature in normal ranges through regulating your sweating and vasoconstriction behavior.
The hypothalamus also helps keep you awake during the day and asleep at night, by controlling your circadian rhythms. A person's sleep cycle is influenced by the time of day and by light exposure.
Your hypothalamus also regulates your appetite and your growth by releasing growth hormone-releasing hormone into your bloodstream. It also controls your sensitivity to glucose by releasing glucocorticoids.
You need the hypothalamus to keep your body in its optimal, healthy state, so it's important for your health. If your hypothalamus is damaged, it can lead to a variety of endocrine problems.
Damage to the hypothalamus may be triggered by certain injuries, medications, or autoimmune diseases. Your doctor can help diagnose these problems and prescribe medication to correct them.
Your doctor can also order tests to check the function of your hypothalamus. These tests include blood and urine tests. They can also use imaging tests to examine the area of your brain that contains the hypothalamus. These tests can reveal if you have any endocrine disorders that involve the hypothalamus.
The Pituitary Gland
The pituitary gland is one of the most important parts of the body’s endocrine system. It is responsible for controlling many of the body’s functions, including metabolism, growth, sexual development, reproduction and blood pressure. It is attached to the bottom of a part of the brain called the hypothalamus, which sends hormone signals to it.
The hormones that the pituitary gland makes include luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone. These hormones help control the production of egg cells in the ovaries in women and sperm cells in the testes in men.
Throughout life, the pituitary gland releases these hormones in a rhythm that varies between people and between days of the week. The hormones rise and fall based on the cycle of daylight and darkness, as well as other factors, such as hunger and sleepiness.
As a result, a person’s testosterone levels may vary from day to day and week to week, but they generally rise at the beginning of the menstrual period, peak during the day and decrease as the day progresses. This rhythm is referred to as the circadian rhythm.
A person’s hormone levels will also change with age. As the person gets older, the gland will release a greater amount of the sex hormone testosterone.
The hormones that the pituitary produces are stored in small pockets within the gland, and are released into the blood stream when they are needed. Some are released continuously, while others are produced in short spurts that last about 1 to 3 hours.
In most cases, the gland produces all the hormones that it needs to function properly. However, the gland may be unable to produce the hormones it needs for normal function because of a pituitary disorder.
These disorders are usually caused by a tumor in the pituitary or other area of the brain near it. Other conditions can interfere with hormone production, such as inflammatory diseases or medications.
The pituitary gland is made up of two parts, an anterior lobe and a posterior lobe. The anterior lobe accounts for about 80 percent of the gland’s size and is the part that is responsible for most of the hormones it releases into the bloodstream. The intermediate lobe, which is also rudimentary in humans, accounts for about 10 percent of the gland’s total size and is mainly responsible for producing melanocyte-stimulating hormone (MSH).
Testicles are oval-shaped organs that sit inside a pouch of skin in the scrotum behind the penis. These organs are part of the male reproductive system and produce sperm, which helps to fertilize a female egg to make a baby.
Your testicles are connected to the inside of your body by a thin cord called a spermatic cord, which contains nerves and blood vessels as well as the vas deferens, which transports sperm to the penis at ejaculation. Each of your testicles is attached to the spermatic cord by a tube called the epididymis, which feels like a soft swelling on the back of the testicle.
The seminiferous tubules of your testes are about two degrees Celsius lower in temperature than the rest of your body, which makes them the ideal place to produce sperm. The tubes are lined with connective tissue stromal cells that contain testosterone secreting Leydig cells.
When testosterone is secreted, it causes sperm to grow and mature into mature sperm cells that can fertilize a female egg. The process is known as spermatogenesis.
Each of your testicles has 200-300 lobules that are filled with a series of one to four highly convoluted seminiferous tubules. These tubules are then interconnected by a layer of connective tissue to form a collecting chamber known as the rete testis, where the sperm are stored until they are ready for transportation out of the scrotum.
The rete testis is lined with testosterone-secreting Leydig cells, Sertoli cells and spermatogenic cells. These cells constantly multiply and through several phases of spermatogenesis, differentiate into mature sperm.
As the sperm cells mature, they travel to another collection chamber within your testicle called the epididymis, which also feels like a soft swelling on the back side of your testicle. As they travel through the epididymis, they pass by ducts that are lined with hair-like projections called cilia. These ducts absorb most of the fluid that helps to move sperm into the epididymis.
If you're a male, it's important to check the condition of your testicles on a regular basis. This can help catch issues early, which can prevent serious problems from developing and affecting your reproductive health.
As we now know, testosterone synthesis is controlled by the hypothalamus and pituitary gland. When testosterone levels are low, the hypothalamus releases gonadotropin-releasing hormone (GnRH), which stimulates the pituitary to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
Once released into the bloodstream, testosterone is transported to target tissues in the testes and prostate where it acts on specific proteins that produce its effects. Much of testosterone is carried bound to a plasma protein called sex hormone-binding globulin (SHBG) and the remainder is free testosterone.
The Leydig cell mitochondria and microsomes of the testes, which are responsible for steroidogenesis, undergo several enzymatic transformations to yield testosterone. These enzymatic processes include cholesterol ester hydrolase, cytochrome P450-mediated testosterone metabolism and sulfation.
In addition to the conversion of cholesterol to testosterone, the enzyme 5-alpha reductase converts testosterone into the steroid dihydrotestosterone (DHT). DHT activates the androgen receptor on the skin, hair, gonadal and prostate tissues to promote the development of male physical characteristics.
During puberty, testosterone stimulates growth of the penis and testes as well as the growth of facial and body hair. It also supports sperm production and prevents the formation of low-density lipoproteins or LDL cholesterol.
Testosterone is produced by the testes in males, and in small quantities by the ovaries in women. In women, the ovaries and adrenal glands account for about a tenth of testosterone synthesized by the testes.
Once produced in the testes, testosterone is transported into the bloodstream to reach the brain and other tissues. It is most commonly transported to the brain, where it stimulates mood, enhances libido and may even positively affect cognition.
Once in the brain, testosterone stimulates neurons to release a chemical that can activate neurosteroid activity and peptide receptors. This can lead to increased sensitivity to the stressors around us and may improve our sense of well-being and motivation.
At around week seven in utero, the sex-related gene on the Y chromosome initiates the development of testicles in male infants. The testicles secrete testosterone to regulate sexual development, muscle density, and bone growth.
Testosterone is a hormone that plays an important role in male sex development and functions during puberty (in the teenage years). The testicles produce a large amount of testosterone, but it is also produced by women's ovaries and adrenal glands.
The brain signals the testes to produce testosterone in response to the release of a gonadotropin-releasing hormone from the hypothalamus. The pituitary gland then releases luteinizing hormone, which travels in the bloodstream to the gonads and stimulates testosterone production and release.
When you are a man, testosterone is produced in your testicles, which are located under the collarbones of your torso. The testicles have special cells that convert cholesterol into testosterone.
Cholesterol is essential for the production of testosterone. The Leydig cells in the testes rely on cholesterol to build and store testosterone. If there is not enough cholesterol flowing through the bloodstream, the testes will not be able to produce testosterone. In some cases, men have low levels of naturally occurring testosterone due to a medical condition. This is called testosterone deficiency syndrome or hypogonadism.