Onset of Puberty
Certainty styling is being phased out topic by topic.Hover over keys for definitions:
Puberty is a short-term event of the central nervous system, which re-initiates positive feedback within the hypothalamic-pituitary-gonadal (HPG) axis and promotes sexual maturation. In the anthropoid primates, sexual maturation proceeds during fetal and early post-natal life, but then the HPG axis is dominated by negative feedback during the juvenile life history stage. The negative feedback delays or suspends sexual maturation for months or years. In humans, the negative feedback begins at about two years after birth. At about nine years of age the HPG axis reverts to positive feedback. The chimpanzee seems to follow a similar age pattern of negative feedback, but re-initiates positive feedback between 6-7 years of age. In most species of primates, puberty is followed within a few months or a year by reproduction. Chimpanzee females in captivity have first birth at about 9 years of age, showing a delay of two years from puberty. In the wild the delay is longer (average first birth at age 13 years). In humans, there is a greater delay between puberty and first reproduction, usually on the order of 5 to 10 years. This is the human adolescent growth stage.
Evolution of Human Growth, , Human Evolutionary Biology, Cambridge ; New York, p.379-395, (2010)
Hypothalamic control of the pituitary-gonadal axis in higher primates: key advances over the last two decades., , J Neuroendocrinol, 06/2008, Volume 20, Issue 6, p.719-26, (2008)
Changes in plasma concentrations of inhibin A and inhibin B throughout sexual maturation in the male chimpanzee., , Endocr J, 12/2000, Volume 47, Issue 6, p.707-14, (2000)
Patterns of human growth, , Volume Cambridge , Cambridge, U.K. ; New York, p.xiv, 455 p, (1999)