Conditions Responsible for Puberty Changes
Role of the Pituitary Gland
pituitary gland produces two hormones: the growth hormone, which is influential
in determining the individual's size, and the gonadotropic hormone, which
stimulates the gonads to increased activity. Just before puberty, there is a
gradual increase in the amount of the gonadotropic hormone and an increased
sensitivity of the gonads to this hormone; this initiates puberty changes.
Role of the Gonads
With the growth and development of the gonads, the sex organs - the
primary sex characteristics - increase in size and become functionally mature,
and the secondary sex characteristics, such as pubic hair develop.
Interaction of the
Pituitary Gland and the Gonads
The hormones produced by the gonads, which have been stimulated by the
gonadotropic hormone produced by the pituitary gland, act in turn on this gland
and cause a gradual reduction in the amount of growth hormone produced, thus
stopping the growth process. The interaction between the gonadotropic hormone
and the gonads continues throughout the individual's reproductive life,
gradually decreasing as women approach the menopause and men approach the climacteric.
Body changes in
Changes in body size - in terms of height and
weight. The greatest increase in height comes in the year following the onset
of puberty. After that growth declines and continue at a slow rate. Weight gain
comes from increase in fat, bone and muscle tissues.
Changes in body proportions - the thin long
trunk of the older child begins to broaden at the hips and shoulders and
Primary sex characteristic in the growth and
development of the sex organs - the gonads or testes and that of the penis in
male. For girls it is the first menstrual flow. This is the discharge of blood,
mucus and broken down cell tissues from the uterus that will occur every twenty
- eight days.
Secondary sex characteristics.