This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Chapter 4 – Growth and Health I. 4.1 Physical Growth • Features of Human Growth o Between birth and 2 years, average height increases from 19 to 32 inches; average weight increases from 7 to 22 pounds. o An interesting rule of thumb is that boys achieve half their adult height by 2 years, and girls by 18 months. o The head and trunk grow faster than the legs o Infants and toddlers have disproportionately large heads and trunks, making them look top-heavy compared to older children. o Virtually all of the body’s muscle fibers are present at birth. o A layer of fat appears under the skin near the end of the fetal period of prenatal development.- Fat continues to accumulate rapidly in baby years, but children become leaner in preschool years. Then they acquire more fat again gradually in early elementary years. o Bone starts to form during prenatal development. What will become bone starts as cartilage , a soft, flexible tissue. During the embryonic period, the center of the tissue turns to bone. o Epiphyses – where the ends of the cartilage structures turn to bone shortly before birth. o Secular growth trends – changes in physical development from one generation to the next. o “Average” physical growth varies not only from one generation to the next, but also from one country to another. o We need to remember that “average” and “normal” are not the same. • Mechanisms of Physical Growth o Growth hormone – 80% of this hormone, which stimulates growth, is secreted while children and adolescents sleep.- Secreted during sleep by the pituitary gland in the brain; form the brain, the growth hormone travels to the liver, where it triggers the release of another hormone, somatomedin, which causes muscles and bones to grow. o Children’s sleep affects their cognitive processes and their adjustment to school...
View Full Document
This note was uploaded on 04/29/2011 for the course PSYC 2350 taught by Professor Miller during the Spring '08 term at University of Houston.
- Spring '08