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 Fig. 3.5 Normal Range and Average Development of Sexual Characteristics in Males and Females

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? 05EjM&mode=related&search=