ADAPTED FROM O’BRIEN 2008 HAPTER 8 C HUMAN GROWTH AND DEVELOPMENT. Margaret J Meehan ADOLESCENCE 11 TO 20 YEARS
WHAT IS ADOLESCENCE? Adolescence is derived from the Latin word adolescere, which means ‘to grow up’. It is seen as a unique transitionary period from childhood to adulthood encompassing not only just physical but also social, emotional and cognitive changes. Puberty refers to the physical and sexual changes that are witnessed during this time. Adolescence encompasses the behavioural, social and emotional aspects: these are influenced by physical and social/cultural factors. Margaret J Meehan
PHYSICAL DEVELOPMENT o o In boys there is an increase in the hormone testosterone and in girls an increase in oestrogen. These hormones create physical and sexual changes. Margaret J Meehan o General Information The process of physiological change is set in motion with the release of hormones by the pituitary gland in the brain, at approx eight or nine years of age.
PHYSICAL DEVELOPMENT There is a difference in the age when males and females start their growth spurt: Girls at approximately ten years of age, hips widen, they gain fat, and they become more ‘curvy’. Boys at approximately 12 years of age, shoulders broaden, legs lengthen and they gain more muscle. Girls tend to be better co-ordinated in their movements, while boys may have greater speed and strength. A balanced diet and adequate rest and sleep are important during these years. Margaret J Meehan
GROWTH PATTERNS In adolescence there is a reversal of proximodistal ( trunk out to extremities) principle of growth. Change begins at the extremities (hands and feet) and works back towards the trunk. So adolescents’ hands and feet grow to their adult size before changes occur to the remainder of their bodies. This time is a period of asynchronous growth ( rapid and uneven ). Margaret J Meehan
THE ADOLESCENCE BRAIN o o o Dr Jay Giedd has discovered that a second wave of synapse formation occurs just before puberty in the prefrontal cortex, whose functions include planning, memory and organization. ‘Pruning’ of the cells occur at this stage and if they are not been used they will be discarded. It has been suggested that the brain is not fully matured until 25 years of age. Margaret J Meehan o The brain undergoes a major growth spurt, particularly in the frontal cortex which is located at the front of the brain.
SEXUAL MATURATION Some of the obvious characteristics associated with adolescence involve the teenager’s changing appearance. Differentiation is made between primary and secondary sexual characteristics. Primary Sexual Characteristics. These are the changes and developments that directly involve the sex organs. Girls – menarche. This refers to the start of menstruation or periods in girls. Average in Ireland is 13. 5. USA is 12. 8. Boys – spermarche. This refers to the first time a boy ejaculates, when males become capable of reproduction. Margaret J Meehan
SEXUAL MATURATION CONTINUED. Ø Ø Secondary Sexual Characteristics These are visible evidence of changes occurring in the adolescent. Girls – Development of breasts Boys – Facial hair and voice change Both – underarm hair Margaret J Meehan Ø Maturation of reproductive organs: In males this includes the growth of the penis and changes to the scrotum and testes. In females it includes the growth of the vagina, ovaries and uterus.
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