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3. Puberty, Health, and Biological Foundations. Puberty. The period of rapid physical maturation involving hormonal and bodily changes that take place primarily in early adolescence. Feedback System of Sex Hormones.
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3 Puberty, Health, and Biological Foundations
Puberty • The period of rapid physical maturation involving hormonal and bodily changes that take place primarily in early adolescence
Feedback System of Sex Hormones LH-RF (lutenizing hormone-releasing factor) and FSH-RF (follicle stimulating hormone-releasing factor) stimulate pituitary gland LH (lutenizing) and FSH (follicle stimulating) stimulate gonads (Testes in males, ovaries in females) Fig. 3.3
The Endocrine System • Hypothalamus • Structure in the brain • Secretes releasing factor • Pituitary Gland • Regulates other glands • Secretes FSH and LH • Gonads • Testes, ovaries • Secretes sex hormones
The Endocrine System Major Endocrine Glands Involved in Pubertal Change Fig. 3.2
Hormones • Powerful chemicals secreted by the endocrine glands; carried through the body by the bloodstream. Androgens: The main class of male sex hormones Estrogens: The main class of female sex hormones
Adrenarche • Involves hormonal changes in the adrenal glands, from about 6-9 years of age • Gonadarche: What most people think of as puberty; involving sexual maturation and development of reproductive maturity • Spermarche: A boy’s first ejaculation of semen • Menarche: A girl’s first menstrual period
Growth Spurt • Occurs 2 years earlier for girls (age 11.5) than boys (13.5) on average • Girl increase 3.5 inches per year, boys about 4, during this period • Weight gain follows roughly same timetable as height gain • Girls gain hip width while boys gain shoulder width
Growth Spurt Pubertal Growth Spurt Fig. 3.4
Sexual Maturation • Males • Increase penis and testicle size • Pubic hair • Voice change • Spermarche • Armpit hair • Facial hair
Sexual Maturation • Females • Breasts enlarge • Pubic hair • Armpit hair • Menarche
Sexual Maturation Normal Range and Average Development of Sexual Characteristics in Males and Females Fig. 3.5
The Age at Menarche has Declined Median Ages at Menarche in Selected Northern European Countries and the United States from 1845 to 1969 Fig. 3.7
Psychological Dimensions of Puberty • Body Image • Hormones and Behavior • Menarche and the Menstrual Cycle • Early and Late Maturation • Are Puberty’s Effects Exaggerated? • http://www.youtube.com/watch?v=Di2Tgx05EjM&mode=related&search=