Child Development Chapter 5: Physical Development, Sleep, and Obesity

Principles of Growth (7)

1. Body parts mature at different rates

2. Functioning becomes increasingly differential

3. Functioning becomes more integrating

4. Each child’s growth curve is different

5. Qualitative + Quantitative Change

6. Children’s bodies are dynamic, changing systems

7. Children’s health embedded within a Multi-layered environment

Physical attainments: Infants

Reflexes to motor skills

• cephalocaudal trend (top → bottom)

• Poximodistal trend (inside → outside) (outward from spine)

Physical Attainments: Early Childhood

Motor skills

• gross

• Fine

Physical Attainments: Middle childhood

• growth + coordination

• Sensitive about physical appearance

Physical Attainments: Early Adolecence

• puberty

• Sexual maturation

Puberty

Period encompassing of physical changes occurring during transition from childhood to adulthood

Phases of Puberty

1. Adrenarche

2. Gondarche

Adrenarche

• ages 6-9

• External physical changes

• BO

Gondarche

• sexual maturation, reproductive maturity

• Girls: Ages 8-13

• Boys: Ages 9-14

Primary Sexual Traits

Girls: uterus

Boys: penis

Secondary Sexual Traits

Girls: Breasts

Boys: facial/chest hair

Pubertal Timing: Family influences

Genes + environment

Pubertal Timing: Cultural Trends

Racial/ethnic differences

Pubertal Timing: Secular trends

Decrease in age

Implication of research on Puberty

1. Guidance for professionals, parents, and the public

2. Disentangle puberty from sexual activity

3. Inform prevention efforts to reduce difficulties as associated with early puberty

Importance of Sleep (9)

1. Energy gains

2. Strengthens immune system

3. Removal of toxins from the brain

4. Release of growth hormones

5. Consolidation of new memories

6. Self-regulation

7. Cognitive ability

8. Cardio-metabolic health

9. Adiposity (fat)

REM

Rapid Eye Movement

• brains active, dreaming

• Body immobile

• Irregular breathing + Heart rate

NREM Sleep

Non-Rapid Eye Movement

• Stage 1: falling asleep/light sleep

• Stage 2: heart rate slows, body temp drops

• Stage 3 & 4: Deep sleep, muscles and tissues repair

Characteristics of Sleep: Newborn

• irregular schedule

• 1-3 hrs awake

• Appears restless while asleep

Characteristics of Sleep: Early Childhood

• Nightmares

• Sleep difficulties

Characteristics of Sleep: Elementary School Aged

• screen time

• Caffeine

Sudden Infant Death Syndrome (SIDS)

Sudden unexplained death of a baby <1 year of age

Risk factors for SIDS

Respiratory infection

Protective Factors for SIDS

Room sharing, breastfeeding, smoke-free environment

Sleep Needs of a newborn

14-17 hrs

Sleep needs of a school-aged child

9-11 hrs

Sleep needs of teens

8-10 hrs

Adolescent Change in Sleep

• lighter sleep

• More adult like pattern of REM sleep

• Daytime sleepiness

• DPP - later bed/wake times

• Later rise in melatonin

Sleep recommendations: infants

• daytime sleep

• Communicate sleep importance with families

Sleep recommendations: School-Age

• Communicate importance of sleep with families

• Encourage students to make steady progress on lengthy assignments rather than cramming

Sleep recommendations: Adolecence

• schedule school events to end at reasonable times

• deliberate start time for high school

BMI

(weight kg)/(height m²)

BMI for children/adolencents

BMI-for-age + sex/gender based on CDC growth charts

Critics of BMI

• Does not measure body fat

• Based on white men

Obesity

For children and adolescents, BMI at or above 95th percentile for sex and age

Prevalence of Obesity in Children

1 in 5

Influences of obesity

• genetic predisposition

• Inadequate exercise

• Race/ethnicity

• Generational incease

Consequences of Obesity

• Physical

• Psychosocial

Psychosocial Consequences of Obesity

• peer teasing/rejection

• Does obesity → depression or does depression → obesity

Prevention of Obesity

Nutrition/diets + exercise

School-based prevention of Obesity

• limit offering of unhealthy meals/snacks

• Offer physical activity daily

• Provide health education