4 Developmental Stages

 First Trimester  Most critical in baby’s health development  Zygote (conception to 2 weeks): genetic blueprint composed of 46 chromosomes – determines sex, hair and eye color, height, and skin tone  Embryo (2-8 weeks): Foundations of the brain, spinal cord, nervous system; heart begins to beat; muscles and backbone forming; evidence of arms, legs, eyes, and ears

 Second Trimester  Capable of physical movement  Body grows  Reflexes start: sucking, swallowing  Third Trimester  Fetus (8-38 weeks): Every body part is present; fetus sleeps, awakens, exercise, turns its head, opens and closes its mouth  Can see and hear; lungs develop by 9 th month; other systems are earlier

 Averages at birth:  7 lbs. (milk gallon)  19 ½ in. long (elbow to fingertip)  Males are usually larger and heavier than females  Baby grows in. in the first year  Gains 1 oz./day  4 months: birth weight is doubled  10 months: imitating sounds and actions

 12 months: weight has tippled  14 months: understands he/she can make things happen by actions  16 months: enjoys games and songs  18 months: vocabulary is formed  2 years: child has reached 50% of his/her adult height; weight has quadrupled – much of the weight is fat

 6 months: Sit  8 months: Creep  10 months: Crawl  12 months: Stand  13 months: Walk

 Physical growth slows, but is still obvious  Average, age 3:  32 lbs.  38-in.  Average, age 6:  48 lbs.  48-in.  Girls are still slightly smaller

 Transition from gross motor skills (throwing a big ball) to small motor skills (using scissors)  Need a lot of physical activity

 Slow, but steady physical growth  Average, age 12  5 ft.  80 lbs.  Girls are taller and heavier by age 12  Refine small muscle and motor skills  Major growth is in cognitive development

 “Raging Hormones”  2-year difference in growth spurts  Girls: age 10 ½  Boys: age 12 ½  Growth spurt:  Extremities grow before main parts; ie: feet before legs ▪ Causes clumsiness  Oil and sweat glands increase production = pimples

 Big Change: Development of Sex Characteristics  Primary – reproductive system develops  Secondary – facial hair, breast development  “Secular Trend”  Physical and sexual changes are occurring at earlier ages than in previous generations