KEY CONCEPT Physical development continues through adolescence and declines with age.

Birth occurs in three stages. Stage one of birth is the dilation of the cervix. Contractions (oxytocin) push cervix open (10 cm or 4 in.) Amniotic sac breaks and leaks amniotic fluid (water broke) if cervix dilates too little, C-section (Cesarean) 33% of all deliveries in U.S. in 2011 were C-section STAGE 1 As regular, strong contractions occur, the cervix dilates and the baby turns.

Stage two is the emergence of the baby. baby usually born headfirst. Breech – feet first oxytocin stimulates milk production (lactation) Colostrum – yellowish fluid released prior to milk contains antibodies from mother STAGE 2 The baby is pushed through the cervix and out of the vaginal canal.

Stage three is the expulsion of the placenta. placenta detaches from uterine wall (afterbirth) contractions helps control bleeding Cut umbilical cord - bellybutton (navel) STAGE 3 Contractions continue, expelling the placenta and helping to control bleeding.

Human growth and aging also occur in stages. Genetics, hormones, lifestyle, environment affect all stages. Key hormones – thyroxin, estrogen, testosterone, human growth hormone HGH During INFANCY, (birth to age 2) growth is rapid 1st birthday – tripled weight, grown 10 in. During CHILDHOOD (2-12 yrs. old) motor and language skills develop Grow about 3 inches and 6 lbs. per year

Genetics, hormones, lifestyle, environment affect all stages. During Puberty, sexual maturity begins Girls – 10-14 yrs. old Boys – 10 -16 yrs. old Can grow up to 6 inches/year Average is 2-3 inches. During ADOLESCENCE (Sexual maturity), growth is rapid and the brain rewired Growth ends at age 15 Girls and age 17 Boys ADULTHOOD and marks the peak of skills and independence, raise families.

Aging is also affected by genetics, hormones, lifestyle, environment. Effects of aging can be reduced with good diet, exercise, and continued learning. Jerry Peel at age 1 1/2 Jerry Peel at age 17 Jerry Peel at age 71