1. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Children Physical Development In Infancy 5

2. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Patterns of Growth Cephalocaudal: size, weight, and feature differentiation gradually work from top to bottom Proximodistal: growth starts at center of body and moves toward extremities How Do Infants Grow and Develop Physically?

3. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Changes in Proportions of the Human Body During Growth How Do Infants Grow and Develop Physically?

4. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Height and Weight Average North American newborn is 20 inches and 7½ pounds –Birth weight doubles by 4 mos; triples at end of first year; First year growth averages 1 inch per month –1½ times birth length at end of 1st year Average 2-year-old –26 to 32 pounds and 32 to 35 inches tall –Growth rate considerably slower in second year How Do Infants Grow and Develop Physically?

5. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Brain Development Extensive growth in utero and infancy Shaken baby syndrome: brain swelling and hemorrhaging PET and MRI scans may harm infant EEG shows brain activity spurt from 1½ to 2 years of age How Do Infants Grow and Develop Physically?

6. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. The Human Brain’s Hemispheres How Do Infants Grow and Develop Physically?

7. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. The Brain’s Four Lobes How Do Infants Grow and Develop Physically? Prefrontal cortex (vision) (body sensations) (voluntary movement and thinking) (hearing)

8. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Brain Development Neuron: info processing nerve cell –Axons and dendrites Myelin sheath: layer of fat cells –Encases and insulates most axons –Myelination continues into adolescence Synapses: tiny gaps –Neurotransmitters How Do Infants Grow and Develop Physically?

9. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. How Do Infants Grow and Develop Physically? 24 months At birth1 month 3 months 15 months The Development of Dendrite Spreading

10. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Brain Development “Blooming” and “pruning” Synaptic overproduction peaks about 4 months after birth Prefrontal cortex overproduction peaks about 1 year of age –Adult density achieved in adolescence –Heredity and environment affect timing How Do Infants Grow and Develop Physically?

11. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. How Do Infants Grow and Develop Physically? 40 70 60 0 50 30 20 10 Synaptic density 10,000 10020030040050060010001500200030004000 6000 8000800 Age in days (from conception) Synaptic Density in Human Brain from Infancy to Adulthood

12. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Early Experience and the Brain Environmental experiences important Infant’s brain waiting for experiences Early experiences and enriched environment Brain heavier in weight with thicker layers Brain develops more neural connections Produces higher neurochemical activity –Impoverished environment Depression is common How Do Infants Grow and Develop Physically?

13. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Sleep Newborn –Sleep varies from 10 to 21 hours each day –Preferred sleep times and patterns vary –20% to 30% have sleep difficulties Culture affects sleep patterns –Length of sleep periods related to sleeping arrangements and parental activities How Do Infants Grow and Develop Physically?

14. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Sleep Regulation of wake-sleep cycle reflects neurological maturation; cycles vary REM (Rapid Eye Movement) sleep –Adults—fifth of sleep –Infants—half of sleep –May promote brain’s development in infancy How Do Infants Grow and Develop Physically?

15. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Sleep Across the Human Life Span 0 24 16 14 12 10 8 6 4 2 Total daily sleep (hours) Older adultsNewbornInfantsChildrenAdolescentsAdults 1-15 days 90 yrs 6 mo 12 mo 18 mo 2 yrs 10 yrs 20 yrs 30 yrs 40 yrs 50 yrs 60 yrs 70 yrs 80 yrs

16. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Shared Sleeping Culture and Sleeping Arrangements –Sharing bed common in many cultures –Crib/separate room common in U.S. –American Academy of Pediatrics discourages co-sleeping because of stress and SIDS risk How Do Infants Grow and Develop Physically?

17. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Sudden Infant Death Syndrome (SIDS) Infant stops breathing, usually during night, and dies without apparent cause –Highest cause of infant death in U.S. –Highest risk is 2 to 4 months of age –Prone position reduces risk –Less common in bedroom with fan and infant who sleeps with pacifier How Do Infants Grow and Develop Physically?

18. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Sudden Infant Death Syndrome (SIDS) Highest risks –Lower birth weight –Siblings with SIDS –Sleep apnea –Lower SES groups –Exposure to cigarette smoke –Placement in soft bedding –Abnormal brain stem functioning –African American and Inuit infants How Do Infants Grow and Develop Physically?

19. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Nutrition Healthy infants need –Loving, supportive feeding environment –50 calories per day per pound of weight –Breast milk (nature’s food) –Gradual increase of chew-and-swallow –More fruits and vegetables, less junk food –Demand feeding becoming more popular –Poor dietary patterns can cause overweight How Do Infants Grow and Develop Physically?

20. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Breast Versus Bottle Feeding Breast milk –Fewer gastrointestinal infections –Lower respiratory tract infections –Reduces effects of asthma in first 3 months –Reduce risk of skin inflammation –May lessen likelihood of obesity –Lowers risk of childhood and adult diabetes –Less risk of experiencing SIDS –Claims of no link to allergy prevention How Do Infants Grow and Develop Physically?

21. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Malnutrition in Infancy Early weaning can cause deficiencies Infants can develop –Marasmus: wasting away of body tissues in infant’s first year, severe lack of protein –Kwashiorkor: deficiency in protein; child’s abdomen, feet become swollen with water –If not fatal, effects are detrimental; lowest SES aided most by supplementary feeding How Do Infants Grow and Develop Physically?

22. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Health Immunization begins in infancy Accident prevention –Increased monitoring needed in infancy –Asphyxiation: leading cause of death under 1 –Choking hazards: toys, chunky foods –Burn risks: sun, electrical, heaters, hot water –Other risks: car accidents, cuts, pet bites How Do Infants Grow and Develop Physically?

23. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Caring for Children Healthy Start Program – Hawaii –Home visits for families: newborns to age 5 –Unstable homes and poverty: Substance abuse Parental depression, low education, unemployment Child abuse –Professional/medical support staff available –Effective results How Do Infants Grow and Develop Physically?

24. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Dynamic Systems Theory Gesell revealed motor skill development –Maturation: unfolding genetic plan Later studies: milestones not fixed Perceptions and motivation lead to new motor skills or fine tuning –Nervous system maturation –Repeated “cycles” of actions –Nature, nurture, and environment interact How Do Infants Develop Motor Skills?

25. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Reflexes Built-in reactions to stimuli –Rooting: reaction to cheek/mouth touched –Sucking: automatic sucking object in mouth –Moro reflex: startle response causes back arching, rapid closing of arms and legs –Babinski reflex: toes fan, foot arches when sole is stroked –Grasping: when something touches palm –Some evolve into more complex actions How Do Infants Develop Motor Skills?

26. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Gross Motor Skills Milestones for large muscle activities –Development of posture –Learning to walk; locomotion, balance, and practice (crawling to walking) –Adapting to slopes –First year milestones: walks easily –Development in second year Skilled and mobile: pull toys, climb stairs Natural exercise: walk quickly, run stiffly How Do Infants Develop Motor Skills?

27. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. How Do Infants Develop Motor Skills? Milestones in Gross Motor Development

28. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Cultural Variations in Guiding Infants’ Motor Development Infants reach motor milestones in different cultures based on activity opportunities –Variations not large –Milestones reached within normal age ranges –Algonquin of Canada Cradle boards –Jamaica Baby massages and limb stretching How Do Infants Develop Motor Skills?

29. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Fine Motor Skills Finely tuned (coordinated) movements –Perceptual-motor coupling necessary Finger dexterity (thumb and forefinger) Two types of grasps: Palmar and Pincer Wrists and hands turn and rotate more –Experience and exercise have impact How Do Infants Develop Motor Skills?

30. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. What Are Sensation and Perception? Sensation –Occurs when information contacts sensory receptors – eyes, ears, tongue, nostrils, and skin Perception –Interpretation of sensation Infants’ Sensory and Perceptual Development

31. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. The Ecological View People directly perceive information in the world around them –Perception allows human-environmental interaction and adaptation –Affordances: opportunities for interaction offered by objects; enhanced by previous experiences Infants’ Sensory and Perceptual Development

32. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Studying Infant Perception Head movement indicates some vision –Visual preference method: Fantz measured length of gaze and patterns of preference in “looking chamber” Habituation: decreased responsiveness Dishabituation: recover habituated response Tracking: applied to vision and hearing –High-amplitude sucking, videos, computers Infants’ Sensory and Perceptual Development

33. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Visual Perception Visual acuity and color in newborn Perceiving patterns – patterns preferred Perceptual constancy – size, shape Depth perception –‘Visual cliff’ study and visual expectations –Binocular cues by age 3 to 4 months Vision: influenced by nature and nurture Infants’ Sensory and Perceptual Development

34. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. Other Senses Hearing: begins in womb –Infancy changes: volume, pitch, localization Touch and Pain Smell: present shortly after birth Taste: may exist before birth Intermodal perception: exists in newborns Perceptual motor coupling Infants’ Sensory and Perceptual Development

35. © 2010 The McGraw-Hill Companies, Inc. All rights reserved. The End 5