Puberty, the Climacteric and the Postmenopause Period

Abstract

The ovaries are almost completely inactive until prepuberty, which occurs at about the age of 8 or 9. At this time the pituitary begins to secrete gonadotropins secondary to the suspension of certain central inhibitory mechanisms which are still poorly understood. These hormones stimulate the ovary to produce significant amounts of estrogens for the first time. Under their influence the uterus enlarges, the corpus increasing in size more than the cervix. The first outward pubertal sign, occurring at age 10 or 11, is the development of breast buds — the thelarche. True puberty begins a short time later with the appearance of pubic hair. This results from an increase in the production of adrenal steroids, which are probably also responsible for the pubertal growth spurt. A year or two after the pubarche, axillary hair appears. Also at this time the estrogens stimulate further development of the vagina and labia minora and cause the pelvis to acquire its characteristic female shape.