CFD 1450 Lecture Notes - Lecture 7: Adrenarche, Genital Stage, Bone Density
CHAPTER 14- PHYSICAL DEVELOPMENT IN ADOLESCENCE
Conceptions of Adolescence
• Biological perspective:
o Puberty: period of storm and stress
o Freud’s genital stage: reawakening of sexual impulses
• Social perspective:
o Role of social and cultural influences
o Wide variability in adolescent adjustment
• Balanced point of view:
o Biological, psychological, and social influences
o Cultural variation in length and demands of adolescence
Phases of Adolescence
• Early
o 11–12 to 14 years
▪ Rapid pubertal change
• Middle
o 14 to 16 years
▪ Pubertal changes nearly complete
• Late
o 16 to 18 years
▪ Full adult appearance, assumption of adult roles
Hormonal Changes in Puberty
• Release of growth hormone (GH) and thyroxine
• Adrenarche: release of adrenal androgens
• Estrogens
o Contribute to girls’ height spurt, development of female sex characteristics,
regulation of menstrual cycle.
o Combine with androgens to stimulate gains in bone density.
• Testosterone
o Is released by boys’ maturing testes.
o Leads to muscle growth, body and facial hair, other male sex characteristics;
also contribute to gains in body size
Sex Differences in Body Growth in Adolescence
Boys
Girls
Growth spurt
Starts age 12½
Starts age 10
Proportions
Shoulders broaden longer
legs
Gain more fat
Muscle–fat makeup
Gain more muscle heart,
lung capacity increase
Gain more fat
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Document Summary
Phases of adolescence: early, 11 12 to 14 years, rapid pubertal change, middle, 14 to 16 years, pubertal changes nearly complete, late, 16 to 18 years, full adult appearance, assumption of adult roles. Improvement in gross-motor development with puberty: girls: slow, gradual gains, boys: dramatic spurt in strength, speed, endurance, boys" use of performance-enhancing drugs: creatine, anabolic steroids, androstenedione, decline in physical education and daily free time physical activity with age. Sexual maturation: primary sexual characteristics, maturation of reproductive organs, girls: menarche, boys: spermarche, secondary sexual characteristics, girls: breasts, boys: facial hair, voice change, both sexes: underarm, pubic hair, other visible parts of the body that signal sexual maturity. Individual differences in pubertal growth: timing of pubertal changes is influenced by, heredity, nutrition and exercise, geographical location, ses and ethnic group, early family experiences, secular trend toward earlier pubertal timing.
