UNIT OBJECTIVES
Understand the relation of puberty to adolescence.
Define hormones.
Delineate differences between primary and secondary sexual characteristics.
Identify the Tanner stages.
Be able to explain the differences between precocious and delayed puberty.
Define teratogens.
HORMONES
One of the defining aspects of adolescence is puberty. This is the series of hormonal changes that actually begin to occur for many people in late childhood. The process involves biological, physical, and hormonal changes that will affect a person for life. Most researchers believe that adolescence is not synonymous with puberty but that the two overlap. Puberty is triggered by hormones. Hormones are chemicals made by the body. They send messages to various other parts of the body outside the nervous system. They help regulate many of the body’s processes.
The hormones that trigger puberty are released in the brain to other parts of the body. The hypothalamus, located deep in the brain, begins this process. This is largely under genetic control and does not occur consciously. These hormones activate another brain area called the pituitary glands. Here the hormones release gonadotropin, which in turn releases sex hormones from the gonads or sex glands.
Testosterone plays a critical role in developing male reproductive tissues such as the testes. It also promotes body hair and muscle and bone mass in both males and females. These are called secondary sexual characteristics. Biological females also have testosterone though not in the concentration that males typically have.
Estrogen is the primary female sex hormone. It is involved in the development and regulation of the female reproductive system and female secondary sex characteristics. While estrogen is present in both males and females, it is usually present at higher levels in females of reproductive age. Estrogen regulates the menstrual cycle. It also causes the development of secondary characteristics such as breasts. Males also have some estrogen, which may be necessary for a healthy libido and sperm development.
Adrenarche is the earliest stage of puberty. It actually occurs as young as ages six and eight. During this period, the adrenal glands secret androgen, causing increased body hair and body odor. Eventually, the skin will become oilier, leading to the likelihood of the development of acne. Acne is often a cause of concern. Usually, though, acne responds well to several home remedies or over-the-counter treatments. However, for a small group of teens, acne can be a severe condition. Adolescents who have problems with acne should consult a health care professional since treatments are available.
Gonadarche begins later, typically between ages 8 and 10 or 11. It includes menarche in females, the first menstrual period, which starts later. For males, this biological process is mirrored in spermache, the first ejaculation of semen. This typically occurs later than gonadarche.
Genes play a necessary pr