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The Male Reproductive System
Transcript of The Male Reproductive System
Uncircumcised vs. Circumcised
The Male Reproductive System
The milky white fluid produced by the prostate gland makes up 35 percent of the semen, protecting the sperm as it travels through the female reproductive tract.
The ejection of semen from the penis is called ejaculation, which occurs when muscles at the base of the bladder and in the prostate and seminal vesicles contract, forcing semen through the vas deferens and urethra.
About 400 million sperm cells in about 3.5 milliliters of semen are released during one ejaculation.
When the semen enters the female, the sperm “swim” upward through the female reproductive system by wiggling their tails.
In its normal state, the penis is a soft, tubular organ that hangs from the front of the body.
Ejaculation can occur when the penis is in an erect state.
An erection is a condition in which the penis becomes larger and stiffer as blood chambers in the penis become filled with blood.
This can be caused by several factors, including sexual excitement or tight clothing, or even for no reason at all.
It is common for a teenage male to experience a nocturnal emission, or “wet dream,” which is erection and ejaculation during sleep, which occurs for various rejections, including sexually arousing dreams.
Other glands and ducts
Each vas deferens is an 18-inch tube that receives sperm from the epididymis.
The two loop over the bladder and join at the urethra, a tube that passes through the penis to the outside of the body.
The urethra carries urine and sperm, but not at the same time. A valve within the urethra prevents the two fluids from mixing.
As the sperm travel through the vas deferens, they combine with fluids produced by other sex glands.
These glands include the seminal vesicles, a pair of glands located near the bladder; the Cowper’s glands, a pair of glands located at the base of the penis; and the prostate gland, which is near the bladder at the midline of the body.
Sperm mixes with the fluids from these glands to produce a liquid known as semen.
Structure and Function
• The male reproductive system is made up of both internal and external organs.
• The internal organs are a series of glands and ducts that store, nourish, and transport the sperm cells once they are produced.
• The external organs produce, store, and release the sperm.
• Once released, a sperm cell must unite with an egg from a female in order for reproduction to occur.
• The joining of a sperm cell with an egg cell, known as fertilization, begins the process of producing a baby.
Sperm production occurs when the hypothalamus signals the pituitary gland to release FSH and LH, which in turn stimulate the cells of the testes to produce testosterone.
These hormones work together to produce sperm within the testes and move them to the epididymis.
As the sperm move through the vas deferens, fluids from the other glands are added to form semen.
The fluid from the seminal vesicles makes up 60 percent of the semen, proving a source of energy for the active sperm.
The clear fluid provided by the Cowper’s glands makes up 5 percent of the semen, lubricating the urethra.
The testes have two major functions:
The production of the male hormone testosterone
The production of sperm.
The testes are made up of coiled tubules in which the sperm are produced.
The testes hang outside the body within a sac of skin called the scrotum, which protects the sperm by keeping the temperature of the testes slightly lower than the normal body temperature.
Sperm need this lower temperature to form and survive.
The penis is the external sexual organ through which sperm leave the body.
The tip of the penis, called the head, or glans, is covered with loose skin, called the foreskin.
In some males the foreskin is removed shortly after birth in a surgical procedure called circumcision.
Circumcision has been performed for both religious and health reasons.
Some physicians think that removing the foreskin helps to keep the penis clean and free from possible infection. Others think regular daily cleanliness will prevent any possible problems.
During the early- to mid-teen years, most boys notice many physical changes taking place in their bodies.
Their voices may deepen
Hair growth may appear on their faces underarms, legs, chests, and above the reproductive organs.
These changes are signs that puberty has begun.
Puberty is a period of sexual development during which males and females become sexually mature and able to produce children. Physical changes occur in a boy’s body, and sperm production begins. Sperm development is controlled by the male hormone testosterone, which is produced by the testes.
• Sperm form in the testes and then move from the testes to the epididymis. The epididymis is a J-shaped tube located on the back of each testis. It is coiled and folded upon itself.
• While in the epididymis, the sperm mature and gain the ability to move. Sperm are then stored in the epididymis for several weeks.
Disorders of the Male Reproductive System
When a person is unable to reproduce, the condition is known as sterility.
In males, sterility may be caused by a number of factors. Some are unable to produce healthy sperm. Environmental factors, such as exposure to certain chemicals, may cause sterility. A sexually mature male who develops mumps may become sterile.
Most men have two testes.
In some, a condition known as undescended testes results when one of the testes does not descend into the scrotum at birth.
It is a risk factor for testicular cancer.
Sperm may not develop properly in an undescended testes because the temperature is too high.
It can be corrected by surgery or treatment with hormones.
It is a common problem in men after middle age.
It can cause some pain and discomfort.
Since the prostate gland surrounds the urethra, an enlarged prostate can make urination painful or difficult.
Surgery is required.
Cancer of the prostate and testes
The most common form of cancer among men is cancer of the prostate.
Surgical removal of the prostate is the usual treatment for this.
Cancer of the testes occurs most commonly in men between the ages of 15 and 34.
Hard lumps, enlargement of the testes, or an unusual thickening of tissue require medical attention.
Treatment is most effective when cancer is in the early stages
A hernia occurs when an organ pushes outward through the wall that normally contains it.
One of the most common hernias is called an inguinal hernia, which occurs when part of the intestine pushes into the scrotum through a weak spot in the wall near the scrotum.
Surgery is necessary to correct this condition.
Keeping the Reproductive System Healthy
• It is important to thoroughly clean the external organs—the penis and the scrotum—daily, preferably during a shower or bath.
• Good health also requires protection and prevention.
• During athletic activities, males should wear a protector or supporter.
• Tight clothing should be avoided.
• To prevent hernias, men should be careful when lifting heavy objects.
• Any signs of pain when urinating, unusual discharges, or sores on the genitals require a medical examination.
• Males should also examine their testes on a monthly basis for signs of cancer.