The Reproductive System
• One essential function of all livings things is
reproduction.
• In humans, the process begins with the
development of reproductive cells in the
bodies of males and females.
• Under the right conditions, a fertilized egg
develops into a baby.
The Male Reproductive System
• In males, the reproductive cells are called
sperm.
• The functions of the male reproductive system
are to produce sex hormones, to produce and
store sperm, and to deliver sperm to the
female reproductive system.
• Fertilization occurs when a sperm cell joins
with a women’s egg.
• Testes-two oval shaped glands, aka, the male
reproductive glands.
• The testes have two major functions-the
production of testosterone and the
production of sperm.
• The sex hormone testosterone affects the
production of sperm and signals certain
physical changes at puberty. i.e. growth of
facial hair.
• The testes hang outside the main body cavity,
within a sac of skin called the scrotum.
• The temperature of the testes is a few degrees
lower than the inside of the body.
• Sperm need this lower temperature to
develop properly and survive.
• In some males, one or both of the testes may
not descend into the scrotum before birth,
known as a condition called undescended
testis.
• Sperm will not develop properly because the
temperature is too high.
• This condition is a risk for testicular cancer.
• Surgery is usually performed before age 2 to
correct this problem.
• The penis is the external sex organ through
which sperm leave the body.
• The tip of the penis is covered with loose skin,
called the foreskin.
• In some males the foreskin is removed shortly
after birth.
• This procedure is known as circumcision.
Sperm Production
• Once a male reaches puberty, millions of
sperm are produced in his testes each day.
• Sperm production begins when the
hypothalamus signals the pituitary gland to
release two hormones.
• Luteinizing Hormone (LH) and FollicleStimulating Hormone (FSH).
• LH signals the testes to begin making
testosterone.
• Testosterone and FSH then trigger the
production of sperm.
• Sperm production continues throughout
adulthood.
The Pathway of Sperm
• Sperm are produced in the testes. They mature
and are stored in the epididymis.
• Sperm travel through the vas deferens to the
seminal vesicles.
• Seminal vesicles add fluid that provides a source
of energy for active sperm.
• The prostate gland adds a fluid that protects the
sperm.
• The bulbourethral glands add fluid that protects
the sperm from acidic conditions in the urethra.
Release of Sperm
• The ejection of semen from the penis is called
ejaculation.
• Ejaculation occurs when the penis is in an
erect state.
• During an erection, the penis becomes larger
and stiffer as blood chambers in the penis
become filled with blood.
• Ejaculation occurs when muscles at the base
of the bladder contract, forcing semen
through the urethra.
• The urethra is a tube that passes through the
penis to the outside of the body.
• Ejaculation is usually accompanied by orgasm,
or sexual climax, which is marked by feelings
of intense pleasure.
Concerns of Puberty
• During puberty, males may notice that they
are more sensitive to sexual stimulation.
• This is a normal part of development and
should not be a cause of concern.
• Nocturnal Emissions, or ejaculation during
sleep is also very common during puberty.
• Nocturnal emissions occur because sperm
production during puberty cause increased
pressure in the reproductive system.
• Masturbation is the touching of one’s own
genitals for sexual pleasure.
• It was once thought that masturbation could
cause acne, mental illness, infertility or other
bad effects. This is not true.
• However, some people today still object to
masturbation on moral or religious grounds.
Keeping Healthy
• Caring for the male reproductive system
involves cleanliness, sexual abstinence,
protection from trauma, self-exams, and
regular medical check-ups.
• A number of serious infections of the
reproductive system and other body systems
can result from sexual contact.
• Healthy choices regarding sexual behavior can
prevent Sexually Transmitted Infections.
• The only way to eliminate your risk of STI’S is
to refrain from sexual activity.
• Males especially teens and young men should
examine their testes for signs of testicular
cancer.
• Testicular cancer is the most common types of
cancer found in males between 15 and 34.
Signs of Testicular Cancer
• Hard lumps or smooth round masses.
• Change in size or shape of testes.
• Lumps are usually found in front or side of
testes.
• Dull aching in the genital area, or feeling of
heaviness in scrotum.
• Testicular cancer is not typically painful when
it first developes.