Chapter 4: Physical Development: Body, Brain, and Perception Physical Growth and the Development of...
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Transcript of Chapter 4: Physical Development: Body, Brain, and Perception Physical Growth and the Development of...
Chapter 4: Physical Development: Body, Brain, and Perception
Physical Growth and the Development of Motor Coordination
By Kati Tumaneng(for Drs. Cook & Cook)
Physical Growth
Average newborn weighs 7.5 lbs. and is 20 inches long.
Birth weight doubles by 5 months. Girls reach 50% of adult weight by age 9, boys by age
11. Length increases by 50% in first year. By age 2 have attained more than 50% of adult height. Growth hormone production peaks during sleep.
Clinical Growth Charts: http://www.cdc.gov/nchs/about/major/nhanes/growthcharts/clinical_charts.htm
Physical Growth
Adolescent Growth Spurt – Increase in growth associated with the onset of puberty. Sparked by sex hormones Occurs at age 12 for females, age 14 for males
Girls briefly taller on average than males around ages 11-14.
Spurt lasts longer for males who average 5 inches taller than females by age 18.
Puberty (AAP): http://www.aap.org/family/puberty.htm
Average Body Weight for Girls and Boys ages 2-20 years
Height Curves for Girls and Boys
Sexual Maturation
Sex hormones stimulate growth in the reproductive system: Androgens – Released in greater concentration in
males. Estrogens – Released in greater concentration by
females. As with growth, sexual maturation earlier for
girls with menarche (first menstrual period) occurring between ages 12 and 13. Most boys enter puberty 1-2 years later.
Over last 100 years, children larger and maturing faster – the secular trend.
Sexual Maturation
Psychological EffectsFor many adolescents, it is a confusing and
awkward time.Changing body image.Girls tend to become less satisfied with
body. Boys tend to become more satisfied.Early-maturing girls and late-maturing boys
often most dissatisfied.
Reflexes: The Infant’s First Coordinated Movements
Reflexes – Involuntary movements that are elicited by environmental stimuli.
Purposes vary – nourishment, exercise, protection Three classes:
Primitive – Help the infant find nourishment or served protective functions during earlier periods of evolution.
Postural – Help infants keep their heads upright, maintain balance, and roll their heads in the direction of their body lean.
Locomotor – Mimic Locomotor movements such as crawling, walking, and swimming.
Begin to disappear as early as 4 months as brain develops more voluntary control.
Voluntary Movements: The Motor Milestones
Cephalocaudal pattern – Head-to-toe 1 month – hold head up3 months – roll over 6 months – sit upright without support7 months – crawling; stand by holding onto
support12 months – first steps
Voluntary Movements: The Motor Milestones
Voluntary Movements: The Motor Milestones
Proximodistal – Nearer-to-farther (from body’s center) 4-5 months – voluntary control over upper arm;
palmer grasp, wrap all 4 fingers and thumb around an object
10 months – more advanced pincer grasp, using thumb opposite forefinger
15 months – can hold a pen; make scribbles using large muscles in upper arms
2-3 years – “tripod” grasp for holding pen 4 years – fine-motor coordination; print a few letters 5 years – more control over printing; write name 6 years – print whole alphabet and numbers to 10
Voluntary Movements: The Motor Milestones
Voluntary Movements: The Motor Milestones
Trends mirror brain developmentDynamic systems theory describes
motor development in terms of complex interacting forces
Neurological development, parental encouragement, cognitive systems, opportunity to exercise, cultural factors all work together to propel development
Nutrition and Eating-Related Problems
Healthy diet includes proteins, carbohydrates, fats, and minerals and vitamins.
Malnutrition – Nutritional deficiency caused by inadequate intake of calories, protein, vitamins, or minerals.
12 million Americans lived in families that “sometimes” or “often” did not have food or money to buy food.
In developing countries, 230 million children under 5 are seriously malnourished.
WHO Database of Malnutrition:http://www.who.int/nutgrowthdb/en/
Nutrition and Eating-Related Problems
Nutrition and Eating-Related Problems
Short- and long-term effects of malnutrition Stunted growth Reduced muscle and body mass in adolescents Female adolescents show delayed menarche Impede fetal growth Babies born with low birth weight, smaller brain
size, and impaired mental and motor behavior Lowered intelligence Perform less well in school Into adulthood, suffer physical and intellectual
deficits that limit ability to earn a good wage
Nutrition and Eating-Related Problems
Obesity – Most frequent nutritional problem in US Percentage of US obese children and adolescents
tripled from 1960s to 2000 64% adults over 20 are obese African American and Hispanic children and teens
higher rates of overweight and obesity than Caucasian Americans
Rely more on fast foods and processed foods Less physically active
Surgeon General Call to Action: http://www.surgeongeneral.gov/topics/obesity/calltoaction/fact_adolescents.htm
Nutrition and Eating-Related Problems
Nutrition and Eating-Related Problems
Eating Disorders – Pressure to be thin high for women and girls. Increasing in males. Anorexia Nervosa – Distorted body image, intense
fear of gaining weight, and refusal to maintain a healthy weight. 1 out of 100 female adolescents.http://www.altrue.net/site/anadweb/
Bulimia Nervosa – Binge eating followed by purging, fasting, or excessive exercise. 2-3 out of 100 female adolescents.
http://www.4woman.gov/faq/Easyread/bulnervosa-etr.htm
Both are likely caused by a combination of genetic, social, and psychological factors.
Chart on Slide 4: from Cook, J. L., & Cook, G. (2005). Child development: Principles and perspectives (1st ed.) (p. 131). Boston: Allyn and Bacon.
Chart on Slide 5: from Cook, J. L., & Cook, G. (2005). Child development: Principles and perspectives (1st ed.) (p. 132). Boston: Allyn and Bacon.
Babies on Slide 10: from Cook, J. L., & Cook, G. (2005). Child development: Principles and perspectives (1st ed.) (p. 137). Boston: Allyn and Bacon.
Babies on Slide 12: from Cook, J. L., & Cook, G. (2005). Child development: Principles and perspectives (1st ed.) (p. 139). Boston: Allyn and Bacon.
Chart on Slide 15: from Cook, J. L., & Cook, G. (2005). Child development: Principles and perspectives (1st ed.) (p. 142). Boston: Allyn and Bacon.
Chart on Slide 18: from Cook, J. L., & Cook, G. (2005). Child development: Principles and perspectives (1st ed.) (p. 142). Boston: Allyn and Bacon.
All other images retrieved from Microsoft PowerPoint Clip Art.