1. Physical Development Principles of Growth for All Stages of Development: In all stages of development, humans follow four main principles of growth. 1.Cephalocaudal principle- The baby develops from the head to the feet. 2.Proximodistal principle- The baby develops from the organs nearest the middle or center outward. 3.The largest muscles develop before the small ones. 4.Human growth and development is based on a combination of genetics and environment.

2. Physical Development Prenatal Development: The normal gestation period for humans is 38 weeks. Several names are given to the developing human. 1.Zygote- from conception to two weeks. 2.Embryo- from two to eight weeks. 3.Fetus- from eight weeks to thirty-eight weeks. 4.Neonate- from birth to two years.

3. ZYGOTE

4. EMBRYO

5. FETUS

6. NEONATE

7. Physical Development Prenatal Development is divided into three trimesters (12-week periods). Environmental factors, such as maternal nutrition, stress, diseases, age, and drug use, affect development and birth size.

8. Physical Development 1.First Trimester- This time is most critical in terms of the developing baby’s health. The embryo is most susceptible to the negative environmental effects. During this time the development of the central nervous system takes place.

9. Physical Development 2. Second Trimester- The developing baby is capable of physical movement. Muscle and bone development begin. Body growth begins, fingers and toes develop, and reflexes, such as sucking and swallowing, are developed.

10. Physical Development 3. Third Trimester- Growth, especially of the brain, is great in this period, and the fetus can see and hear. Although the lungs are not fully developed until the ninth month, most other systems are well developed.

11. Physical Development Neonatal Development: The newborn (neonate) is a miraculous, unique individual with many impressive features. The baby is born with only a few innate reflexes but quickly matures and changes.

12. Physical Development At birth, males and females weigh about 7 lbs. and average 19’’ long. (This is approximately the weight of a gallon of milk and the length from the elbow to the fingertip.) Males are slightly heavier and larger than females at birth. Physical growth is rapid during the first two years of life.

13. Physical Development The baby grows 10-12’’ in the first year. By age 2, the child has reached 50% of his adult height. The newborn gains an ounce a day. By four months, his weight is doubled; it has tripled by one year and quadrupled by age two. Much of this early weight gain is fat. Fat production slows down after nine months.

14. Physical Development In general, infants develop according to the following steps: 1.Sit- 6 months 2.Creep- 8 months 3.Crawl- 10 months 4.Stand- 12 months 5.Walk- 13-14 months

15. Physical Development Preschool Development (Ages 2-6) – During this stage, physical growth slows down by is still very obvious. By age 3, the average child weights 32 lbs. and is 38’’ tall. By the end of this period, at age 6, the average child weighs 48 lbs. and is 48’’ tall. Girls are still slightly smaller and shorter than boys.

16. Physical Development Middle Childhood Development (Ages 6-12) – During this stage, physical growth is slow but steady. By age 12, the child is approximately 5 feet tall and weighs 80 lbs. (Of course, there is much variance in height and weight at this age.) Girls are taller and heavier than boys by the end of middle childhood. Children refine small muscle and motor skills during this period. – Between the ages of 6-12, the major growth and change is in cognitive domain.

17. Physical Development Adolescent Development (Ages 10 or 11-18) – During this period of “raging hormones,” there is a two-year difference in growth spurts. Girls experience this growth spurt at approximately age 10 and boys at 12. The growth spurt is asynchronous; the extremities grow before the main parts, such as feet before the legs and the hand before the arms. This is the cause for the awkward, clumsy stage many adolescents experience. At this time, the oil glands and sweat glands also increase in production, causing pimples.

18. Physical Development Next come the big changes, the development of sex characteristics. Changes in primary sex characteristics, those directly related to reproduction, occur. Also, it is during this time that secondary sex characteristics (those not necessary for reproduction), such as growth of facial hair and breast development, occur.

19. Why does this matter? Think about which grade level you want to teach. What characteristics of physical development will your future students have? – How will knowledge of this impact your approach to teaching this age group? Why is knowledge of physical development helpful to all teachers?

20. Physical Development There is an important concept titled “the secular trend” which indicates that physical and sexual changes are occurring at earlier ages than in previous generations.