PHYSICAL DEVELOPMENT IN INFANCY

1. Chapter 4 PHYSICAL DEVELOPMENT IN INFANCY

2. Learning Objectives

3. GROWTH AND STABILITY

4. Physical Growth: The Rapid Advances of Infancy Infants grow at a rapid pace over the first two years of their lives (see Figure 4-1) • 5 months: average birthweight doubles to around 15 pounds • 1 year: weight triples to about 22 pounds • End of 2nd year: average child weighs around four times as much as he or she did at birth

5. See how they grow…

6. Physical Growth: The Rapid Advances of Infancy Not all parts of an infant's body grow at the same rate • Birth: head accounts for one-quarter of the newborn's entire body size • During 1st and 2nd year: rest of the body begins to catch up

7. An Interesting Head Count

8. Are there gender and ethnic differences in infant weight and length?

9. Physical Growth:The Rapid Advances of Infancy Can you give an example of each principle?

10. Nervous System and Brain:The Foundations of Development • Neurons are the basic cells of the nervous system • Nervous system comprises the brain and the nerves that extend throughout the body

11. How great brains grow! Birth • 100-200 billion neurons • Relatively few neurons-neuron connections During first two years • Billions of new connections established and become more complex

12. Use it or lose it! Babies are actually born with many more neurons than they need • Although synapses are formed throughout life, based on our changing experiences, the billions of new synapses infants form during the first two years are more numerous than necessary • Synaptic pruning • Unused neurons are eliminated • Allows established neurons to build more elaborate communication networks with other neurons • Development of nervous system proceeds most effectively through loss of cells • Myelin

13. Neuron Networks

14. Coming to terms with your brain…

15. Form and Function: Brain Growth • Neurons reposition themselves with growth, becoming arranged by function • Cerebral cortex • Subcortical levels

16. Don't shake the baby! Shaken Baby Syndrome • Brain sensitive to form forms of injury • Shaking can lead to brain rotation within skull • Blood vessels tear  severe medical problems, long-term disabilities, and sometimes death

17. Brain Development: Influences and Definitions

18. What do babies do all day? Integrating the bodily systems: Life cycles of infancy • Rhythms: repetitive, cyclical patterns of behavior • Wake • Sleep • Eat • Eliminate

19. Rhythms and States State • One of major body rhythms • Degree of awareness infant displays to both internal and external stimulation • Change in state alters amount of stimulation required to get infant's attention • Electrical brain waves can be measured by electrocephalogram (EEG)

20. Primary Behavioral States

21. Primary Behavioral States

22. Sleep: Perchance to Dream Major state • 16-17 hours daily (average); wide variations Different than adult sleep • 2 hour spurts; periods of wakefulness • Cyclic pattern • By 16 weeks sleep about 6 continuous hours; by 1 year sleep through night • (See Table 4-2)

23. A Quick Review of Behavioral States

24. REM Sleep • Period of active sleep • Closed eyes begin to move in a back-and-forth pattern • Takes up around one-half of infant sleep • May provide means for brain to stimulate itself through autostimulation

25. REM Sleep Through the Lifespan

26. Did you find examples in the text that suggest that cultural practices affect infants’ sleep patterns?

27. SIDS: The Unanticipated Killer • Sudden infant death syndrome (SIDS) is a disorder in which seemingly healthy infants die in their sleep • SIDS strikes about 2,500 infants in the United States each year • Although it seems to occur when the normal patterns of breathing during sleep are interrupted, scientists have been unable to discover why that might happen

28. SIDS

29. Declining Rates of SIDS

30. SIDS is found in children of every race and socioeconomic group and in children who have had no apparent health problems Back-to-sleep is important!

31. Review and Apply

32. Review and Apply

33. Review and Apply

34. MOTOR DEVELOPMENT

35. Motor Development • Shape and proportions of newborn babies are simply not conducive to easy mobility • Young infants lack the strength to raise large heads • Movement is further impeded because limbs are short in relation to the rest of the body • Infant bodies are mainly fat, with a limited amount of muscle; the result is a lack strength

36. Motor Development BUT • At birth newborns have an extensive repertoire of behavioral possibilities brought about by innate reflexes, and their range of motor skills grows rapidly during the first two years of life

37. Reflexes: Inborn Physical Skills Reflexes • Learned, organized involuntary responses that occur automatically in presence of certain stimuli

38. Some Basic Reflexes in Infants

39. Some Basic Reflexes in Infants

40. Why do reflexes come and go?

41. Ethnic and Cultural Differences and Similarities in Reflexes Reflexes • Genetically determined • Universal Cultural variations in ways displayed • Moro reflex Serves • Diagnostic tool • Social function • Survival function

42. Milestones of Motor Development

43. Dynamic Systems Dynamic systems theory • Describes how motor behaviors are assembled • Motor skills do not develop in vacuum • Each skill advances in context of other motor abilities • As motor skills develop, so do non-motoric skills • Theory places emphasis on child's own motivation (a cognitive state) in advancing important aspects of motor development

44. Developmental Norms Comparing Individual to Group Norms: • Represent the average performance of a large sample of children of a given age • Permit comparisons between a particular child's performance on a particular behavior and the average performance of the children in the norm sample • Must be interpreted with caution • Brazelton Neonatal Behavior Assessment Scale (NBAS)

45. Developmental DiversityCultural Dimensions of Motor Development • Using information from your text, answer the following: Does earlier emergence of a basic motor behavior in a given culture has lasting consequences for specific motor skills and for achievements in other domains?

46. Nutrition in Infancy Fueling Motor Development • Without proper nutrition, infants cannot reach physical potential and may suffer cognitive and social consequences • Infants differ in growth rates, body composition, metabolism, and activity levels

47. So what is a healthy caloric allotment for infants? • About 50 calories per day for each pound of weight • Most infants regulate their caloric intake quite effectively on their own • If are allowed consume as much they seem to want, and not pressured to eat more, they will be healthy

48. Malnutrition Malnutrition • Condition of having improper amount and balance of nutrients, produces several results, none good • More common in children living in many developing countries • Slower growth rate • Chronically malnourished during infancy = later lower IQ score

49. Underweight Children

50. Are problems of malnourishment restricted to developing countries?