Describe the hormonal changes which occur at puberty in humans.

On average people between age of 11 to 15 go through a
period of rapid growth and physical change particularly in sex related characteristics.
This period of rapid growth or changes in sex related organs and characteristics is
called puberty. The Range of age given above is average, but in reality there are
variations from person to person. Also there are difference in average age of puberty
between people of different races. Further girls achieve age of puberty earlier than
boys.

Growth that takes place is controlled by hormones.
When the puberty starts secretion of gonadotropin-releasing hormone is greatly
increased. This hormone acts on the anterior lobe of the pituitary gland, stimulating it
to secrete the gonadotropic hormones and luteinizing hormone.  These hormones, in turn,
act on the testicles in males and the ovaries in females. These sex gland grow and begin
to secrete large amounts of sex hormones. The cortex of adrenal glands also secretes
some sex hormones.

The sex hormones help trigger a person's
rapid growth in height and weight.  Androgens promote maturity of male sex organs male
sexual behaviour.  These also stimulate chancges in male characteristics as a deep voice
and a beard.

Oestrogens stimulate growth of female sex
organs establish female sexual behaviour.  They also stimulate the development female
characteristics, such as full breasts and wide hips.