Sexual Biology.
This secton deals with various biological aspects which everyone should
be aware of like human physiology, hormonal secretion and their functions,
the male sex organs and the female sex organs. We have tried to give an
accurate picture but in case you need more details, we advise you to pick
up a book of biology.
Male Sex Organs
Female Sex Organs
Pregnancy
HORMONES
Nobody can will himself to grow or to stop
growing; nobody can turn off his digestive system simply by
thinking about
it; nobody can cause
his cells to reproduce themselves simply by concentrating. Yet
all of these changes in the body are just as much under the control
of
the brain as is the conscious decision whether or not to reach
out for an extra helping of potatoes.
Instead of being responses
to a message sent by the brain along the nerve pathways, these
changes and many others are responses
to messages delivered in a kind of code by chemicals known
as hormones.
These coded signals control the inner rhythms of
the body; such as those which take place in a woman's body
during menstruation.
They are responsible for the bursts of energy produced during
emergencies for rapid growth infancy, a slower rate of growth
during childhood and the final explosion of growth during adolescence.
Hormones
are produced and released in response to instructions from
the brain, by various organs and tissues but the chief producers
are the endocrine glands. Small and powerful, the endocrines
pump their secreted hormones directly into the bloodstream.
The
blood then carries them to the places where they take effect.
There
are six main sets of glands in the endocrine system the pituitary,
thyroid, parathyroids, adrenals, islets of Langerhans
in the pancreas and gonads (testis in men and ovaries in women).
They are ductless glands that secrete their bio-chemical substances
called hormone (meaning "I excite"), directly in the
blood-stream.
Because of their importance in human sexuality,
three glands : pituitary, adrenal and the gonads are important.
PITUITARY GLAND
The pituitary gland is a small gland
- about one-half inch long - weighing less than half a gram
and is
located in the skull at the base of the
brain. Not all hormones secreted by the pituitary have been identified
or their action defined, but the best known ones are:
The growth
hormone, referred to as HGH (human growth hormone), affects
the growth and shaping of the skeleton.
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