Puberty

PUBERTY

As mentioned, the burst of male hormones in male fetuses affects the brain (hypothalamus), changing the pattern of hormonal secretion and behavior. In both sexes, the gonads (ovary and testis) remain dormant until they are activated by secretions from the pituitary to bring about the final maturation of the reproductive system. This period of final maturation is known as adolescence. It is also known as pu-berty. However, physiologically, puberty is the periodwhen the endocrine and gamete-producing functions of the gonads have first developed to where repro-duction is possible. The age at puberty has decreased over the years. In recent years, puberty tends to occur between the ages of 8 and 13 in girls and 9 and 14 in boys.

In females, adolescence begins with the develop-ment of breasts and axillary and pubic hair, followed by the first menstrual period (menarche). The phys-iologic changes that occur with the menstrual cycle are described later.

The body changes that occur at puberty in males are enlargement of the external and internal geni-talia, voice changes, hair growth, mental changes, and changes in body conformation and skin. The pe-nis increases in length and width and the scrotum be-comes pigmented and rugose (wrinkled). All internal organs increase is size. The larynx enlarges, with thickening of the vocal cords and deepening of the voice. Body hair, in general, increases and hair begins to appear on the face, axilla, chest, and pubis. Men-tally, the person becomes more interested in the op-posite sex. There is a predisposition to acne as the se-baceous gland secretions thicken and increase.