1. Birth occurs in three stages. Stage one of birth is the dilation of the cervix. – contractions push cervix open – if cervix dilates too little, C-section done STAGE 1 As regular, strong contractions occur, the cervix dilates and the baby turns.

2. Stage two is the emergence of the baby. –baby usually born headfirst –oxytocin stimulates milk production STAGE 2 The baby is pushed through the cervix and out of the vaginal canal.

3. Stage three is the expulsion of the placenta. –placenta detaches from uterine wall –contractions helps control bleeding STAGE 3 Contractions continue, expelling the placenta and helping to control bleeding.

4. Human growth and aging also occur in stages. Genetics, hormones, lifestyle, environment affect all stages. – during infancy, growth is rapid – during childhood, motor and language skills develop

5. Genetics, hormones, lifestyle, environment affect all stages. –during puberty, sexually maturity begins –during adolescence, growth is rapid and the brain rewired –adulthood marks the peak of skills and independence

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