Puberty (cont.)
What are the physical changes of puberty?
The sexual development of puberty has a typical pattern in both boys and
girls, with a generally predictable sequence of changes. In most girls, the
first sign of puberty is the beginning of breast development, which occurs at an
average age of approximately 11 years. In girls, the growth of pubic hair
typically begins next, followed by the growth of hair in the armpits. A minority
of girls, however, begin to develop pubic hair prior to breast development. The
onset of menstruation (having periods) usually happens last and usually occurs
around two and a half years after the onset of puberty.
A regular pattern of ovulation, corresponding to achievement of fertility,
usually develops rapidly once a girl begins having menstrual periods. However,
girls who have a later onset of menstruation (after age 13) tend to have lower
rates of regular ovulation in the years following the onset of menstruation.
Studies have shown that one-half of adolescent girls who first begin to
menstruate after age 13 will not ovulate regularly over the next four and a half years.
In boys, an increase in the size of the testicles is the first change
observed at the onset of puberty. Enlargement of the testicles begins at an
approximate average age of 11 and a half years in boys and lasts for about six months.
After enlargement of the testicles, the penis also increases in size.
Enlargement of the testicles and penis almost always occurs before the
development of pubic hair. The next stage is the growth of pubic hair and hair
in the armpits. Next, the voice becomes deeper and muscles increase in size. The
last step is usually the development of facial hair.
Fertility is achieved in males near the onset of puberty, when a surge in
testosterone triggers the production of sperm.
The sequence of changes in puberty has been characterized by physicians and
is referred to as sexual maturity rating (SMR) or Tanner stages, named after a
physician who published a description of the sequence of physical changes in
puberty in 1969. Tanner stages are determined by the development of the
secondary sex characteristics and encompass changes in the size and appearance
of the external genitalia, the development of pubic hair, and breast development
in girls. Tanner stages allow doctors to classify the extent of development of
sex characteristics into five distinct steps ranging from stage 1 (prepubertal)
to stage 5 (mature adult type).
Next: What other changes in the body occur during puberty? »
- leuprolide, Lupron - Information on the drug leuprolide (lupron) prescribed for the treatment of prostate cancer, endometriosis, fibroids, and central precocious puberty.
- Diabetes - Learn about type 1 and 2 diabetes (Diabetes Mellitus) symptoms including increased urination, thirst, weight loss, fatigue, nausea, vomiting, skin infections, and blurred vision. Causes and diagnosis information is provided in the information.
- Anemia - Read about anemia (low blood cell count, low hemoglobin) causes like iron deficiency, stomach ulcers, medications, colon cancer, trauma, vitamin 12 or folate deficiency, leukemia, myltiple myeloma and more.
Latest Medical News
Kids Health RSS