in a Man
Hormones in a
male play a vital role in sexual and reproductive
activity. Hypothalamus is situated in the brain which
releases a hormone to stimulate pituitary gland. Even
though there is regular release of hormones from Hypothalamus,
decline and raise in accordance with the emotions,
feeling pertaining to their own visual and sensory
perceptions. The stimulated pituitary releases two
hormones. The Follicular stimulating hormone and Luetinising
hormones stimulate the testes for sperm production
and release of “Testosterone” hormone.
Sperm begin life
in the testes in cells called Sertoli cells.At the
beginning of a sperm's life cycle, hormones develop
its head and tail. The sperm then escapes from the
Sertoli cell into the epididymis located behind the
testes. For three weeks, a sperm travels through the
epididymis in an energizing fluid containing fructose.
As the sperm swims through this fluid, it matures
and acquires the ability to swim and move back and
forth. A mature sperm has a head that contains the
man's DNA - his genetic material - and a tail that
rapidly moves from side to side, propelling it forward.
When a man ejaculates
during sex, muscular contractions push the sperm out
of the epididymis to channels called the vas deferens.
The sperm then move to the ejaculatory ducts and out
the urethra,the passage through which urine and semen
are passed from the body.
Just before ejaculation, the sperm in
the ejaculatory ducts mix with fluids that come from
the prostate gland and from glands called the seminal
vesicles, creating semen. During orgasm, the seminal
vesicles push the semen forcefully out into the urethra.
A muscle in the bladder also locks shut to prevent
the semen from traveling backward into the bladder
and mixing with urine. The semen moves from the urethra
to a holding area at the bottom of the penis, where
muscles propel it out of the penis.
How a sperm fertilizes the egg ?
Of the 100 to
300 million sperm released when a man ejaculates,
only about 40 survive the trip through the acidic
environment of the vagina and cervix. The woman's
thick cervical mucous can also be a barrier. But during
ovulation, the woman's mucous thins and allows the
sperm to travel more freely.
After it bores through the cervical mucous, the sperm
trigger the acrosome (a special membrane located on
their heads), and it dissolves and releases special
enzymes. These enzymes allow the sperm to penetrate
the tough coating surrounding the egg in the fallopian
tubes. Only one sperm ultimately fertilizes the woman's