Hormone and Later Female Puberty

1.1 INTRODUCTION TO PUBERTY
Puberty is the process of physical changes by which a child 's body becomes an adult body capable of reproduction, it is the time at which a growing boy or girl begins the process of sexual maturation. At puberty, a young man 's body begins making sperm and he starts to be able to ejaculate, which is Semen coming out from his penis when he is sexually excited. If he has sexual intercourse (sex) with a young woman, he can make her pregnant. In a strict sense, the term puberty (derived from the Latin word puberatum (age of maturity, manhood)) refers to the bodily changes of sexual maturation rather than the psychosocial and cultural aspects of adolescent development. Adolescence is the period of psychological and social transition between childhood and adulthood. Adolescence largely overlaps the period of puberty, but its boundaries are less precisely defined and it refers as much to the psychosocial and cultural characteristics of development during the teen years as to the physical changes of puberty.
Puberty involves a series of physical stages or steps that lead to the achievement of fertility and the development of secondary sex characteristics, the physical features associated with adult males and females (such as the growth of pubic hair). While puberty involves a series of biological, or physical, transformations, the process can also have an effect on the psychosocial and emotional development of the adolescent.
Puberty is initiated by hormone (which are chemicals) signals from the brain to the gonads (the ovaries and testes). In response, the gonads produce a variety of hormones that stimulate the growth, function, or transformation of brain, bones, muscle, blood, skin, hair, breasts, and sex organs.
Growth accelerates in the first half of puberty and stops at the completion of puberty. Before puberty, body differences between boys and girls are almost entirely restricted to the genitalia. During puberty, major

References:  A.J. Giannini and A.E. Slaby (1981). "A Speculation on Puberty, Marriage Contracts and Frozen Food"; pp.51–52.  Abbassi, V (1998). "Growth and normal puberty.”; Paediatrics ; pp. 507–513.  Alfred Charles Kinsey; Wardell Baxter Pomeroy; Clyde Eugene Martin (1948). Sexual Behavior in the Human Male; pp. 190-205.  Alice Klein (2004)  Ann Byers (2007). "How Do Boys ' Bodies Change during Puberty?"; Frequently Asked Questions about Puberty; pp. 16–25  Apter, D (1980)  Armstrong, SM and Redman, JR (1991). "Melatonin: a chronobiotic with anti-aging properties?".Medical hypotheses ; pp. 300–309.  B  B.S. Mustanski; R.J. Viken, J. Kaprio, L. Pulkkinen, R.J. Rose (2004). "Genetic and Environmental Influences on Pubertal Development; Longitudinal Data from Finnish Twins at Ages 11 and 14"; Developmental Psychology; pp. 1188–1198.  Byers (2007), "Data from Alfred Kinsey 's studies". The Kinsey Institute for Research in Sex, Gender, and Reproduction. Retrieved 30 November 2008.  Christine Opping (1973). "Notes on Cultural Aspects of Menstruation in Ghana"  Clayton, PE and Trueman, JA (2000)  Comings, DE; Muhleman, D; Johnson, JP; MacMurray, JP (2002). "Parent-daughter transmission of the androgen receptor gene as an explanation of the effect of father absence on age of menarche.". Child development ; pp. 1046–1051  D  D.E. Comings; D. Muhleman, J.P. Johnson, J.P. MacMurray (2002). "Parent–Daughter Transmission of the Androgen Receptor Gene as an Explanation of the Effect of Father Absence on Age of Menarche"; Child Development ; pp. 1046–1051.  David Osei-Adu.(2009) "Puberty rites"; GhanaWeb. Retrieved 2 May 2010.  Dennis M  Diana Zuckerman; Paul Brown, Laura Walls (2008). "Are Bisphenol A (BPA) plastic products safe for infants and children?"; National Research Centre for Women & Families. Retrieved 26 November 2008.  Finley, and Harry (2006). "Average age at menarche in various cultures"; Museum of Menstruation and Womens Health; Retrieved 2007-08-02.  Gungor, Neslihan; Arslanian SA (2002). "Chapter 21: Nutritional disorders: integration of energy metabolism and its disorders in childhood". ; Paediatric Endocrinology; pp. 689–724.  H. Wessells H; T.F. Lue; J.W. McAninch (1996). "Penile Length in the Flaccid and Erect States: Guidelines for Penile Augmentation"; Journal of Urology; pp. 995–997.  Harry Finley (2003). "Average Age at Menarche in Various Cultures"; Museum of Menstruation and Women 's Health.  J. Chen; A. Gefen; A. Greenstein; H. Matzkin; D. Elad (2000). "Predicting Penile Size during Erection"; International Journal of Impotence Research; pp. 328–333.  J. Jeff Malta (2004). "Five stages of puberty in girls?"; Puberty 101. Retrieved 1 December 2008.  J. Kaprio; A. Rimpelä, T. Winter, R.J. Viken, M. Rimpelä, R.J. Rose (1995)."Common Genetic Influences on BMI and Age at Menarche"; Human Biology; pp. 739–753.  J.M. Tanner and P.S. Davies (1985). "Clinical Longitudinal Standards for Weight and Height Velocity for North American Children"; Journal of Pediatrics; pp. 317–329.  Jones and Kenneth W. (2006). Smith 's Recognizable Patterns of Human Malformation; pp. 2-6.  Kenneth W. Jones (2006). Smith 's Recognizable Patterns of Human Malformation; pp. 87-92.  Kinsey (2009), Sexual Behavior in the Human Male; pp. 299-301  Kiyoko Kakumasu (2008)  Krueger, H and Osborn, L (1986). "Effects of hygiene among the uncircumcised.". The Journal of family practice; pp. 353–367.  L.K  Lehrer, S (1983). "Puberty and resonance: a hypothesis.". The Mount Sinai journal of medicine, ; pp.39–43.  Lehrer, S (1984)  Lehrer, S (1986). "Rats on 22.5-hr light:dark cycles have vaginal opening earlier than rats on 26-hr light: dark cycles." Journal of pineal research ; pp. 375–378.  MacGillivray, MH; Morishima, A; Conte, F; Grumbach, M; Smith, EP (1998)  Marshall, William A.; Tanner, JM (1986). "Chapter 8: Puberty". ; Human Growth: A Comprehensive Treatise ; pp. 171–209.  Marshall, Human Growth; pp  McKenna, and Phil (2007). "Childhood obesity brings early puberty for girls". New Scientist. Archived from the original on 2008-04-19. Retrieved 2010-05-22.  Meister, B and Håkansson, ML (2001). "Leptin receptors in hypothalamus and circumventricular organs.". ; Clinical and experimental pharmacology & physiology ; pp. 610–617.  Molly M. Ginty (2007). US girls ' early puberty attracts research flurry; Women 's eNews. Retrieved 26 November 2008.  Molly, M. Ginty, "US Girls ' Early Puberty Attracts Research Flurry", Women 's eNews  Mustanski, BS; Viken, RJ; Kaprio, J; Pulkkinen, L; Rose, RJ (2004)  Neill, J. D. (2001). "In Memoriam: Ernst Knobil (1926-2000)". Endocrine Reviews ; pp. 22-53.  Nelson RJ  Neslihan Gungor and S.A. Arslanian (2002). "Nutritional Disorders: Integration of Energy Metabolism and its Disorders in Childhood"; Paediatric Endocrinology; pp. 689–724.  P.E. Clayton and J.A. Trueman (2000). "Leptin and Puberty"; Arch. Dis. Child; pp. 1–4.  P.H. Whincup; J.A. Gilg, K. Odoki, S.J.C. Taylor, D.G. Cook (2001). "Age of Menarche in Contemporary British Teenagers: Survey of Girls Born between 1982 and 1986"; British Medical Journal; pp. 1095–1096.  Phil McKenna (2007). "Childhood obesity brings early puberty for girls"; New Scientist. Retrieved 26 November 2008.  Plant, TM (2001). "Leptin, growth hormone, and the onset of primate puberty.". The Journal of clinical endocrinology and metabolism ; pp. 458–460.  Rivest, RW (1991)  Rosenfield and Robert L. (2002). "Chapter 16: Female puberty and its disorders". ; Paediatric Endocrinology ; pp. 455–518.  S.A. Treloar and N.G. Martin (1990). "Age at Menarche as a Fitness Trait: Nonadditive Genetic Variance Detected in a Large Twin Sample"; American Journal of Human Genetics; pp. 137–148.  Siegel, MJ and Surratt, JT (1992)  Sizonenko, PC and Aubert, ML (1986). "Neuroendocrine changes characteristic of sexual maturation.". Journal of neural transmission. ; pp. 159–181.  Southam, AL and Richart, RM (1966)  Steve Dowshen (2007). "Male reproductive system"; Teens Health, The Nemours Foundation 's Center for Children 's Health Media. Retrieved 29 November 2008.  Steven Dowshen (2007). "I 'm a guy... so how come I 'm developing breasts?"; Teens Health, The Nemours Foundation 's Centre for Children 's Health Media. Retrieved 2 December 2008.  Steven Dowshen (April 2007). "Everything you wanted to know about puberty"  Styne and Dennis M  T., Dumanoski, D. and Myers, J.P. (1996) . Our Stolen Future.  T.M. Plant (2001). "Leptin, Growth Hormone, and the Onset of Puberty"; J. Clinical Endocrinology Metabolism; pp. 458–460.  Tom Scheve (2008). "Puberty rites around the world"; How Stuff Works. Retrieved 2 May 2010.  Treloar, SA and Martin, NG (1990). "Age at menarche as a fitness trait: nonadditive genetic variance detected in a large twin sample.". American journal of human genetics ; pp. 137–148.  V. Abbassi (1998). "Growth and Normal Puberty"; Paediatrics; pp. 507–511.  Vilaplana, J; Madrid, JA; Sánchez-vázquez, J; Campuzano, A; Cambras, T; Díez-noguera, A (1995). "Influence of period length of light/dark cycles on the body weight and food intake of young rats.". Physiology & behavior ; pp. 9–13.  W.A. Schonfeld (1943). "Primary and Secondary Sexual Characteristics: Study of their Development in Males from Birth through Maturity, with Biometric Study of Penis and Testes”; American Journal of Diseases of Children; pp. 535-538.  Whincup, P H; Gilg, JA; Odoki, K; Taylor, SJ; Cook, DG (2001). "Age of menarche in contemporary British teenagers: survey of girls born between 1982 and 1986". BMJ ; pp. 1095–1099.  William A. Marshall and J.M. Tanner (1986). Human Growth: A Comprehensive Treatise; pp. 176–179.  Xiaojia Ge; Misaki N. Natsuaki, Jenae M. Neiderhiser, David Reiss (2007). "Genetic and Environmental Influences on Pubertal Timing; Journal of Research on Adolescence; pp. 767–788.  Yellon, SM; Newman, SW (1991)  Z. Janczewski and L. Bablok (1985). "Semen Characteristics in Pubertal Boys: Semen Quality after First Ejaculation"; Archives of Andrology ; pp. 199–205.  Zuckerman and Diana (2009). "Early Puberty in Girls"; National Research Centre for Women and Families. Retrieved 2010-07-13.