dev psych.ch3.keynote
TRANSCRIPT
Slide 1
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
1
A Topical Approach to LIFE-SPAN DEVELOPMENT
John W. Santrock
Chapter Three:
Physical Development
and Biological Aging
Slide 2
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
2
Body Growth and Change
• Patterns of growth– Cephalocaudal pattern – from top (head) and
gradual to bottom – Proximodistal pattern – center of body outward
to extremities– Growth rate affected by SES, birth order, and
maternal habits during prenatal development– Growth hormone deficiency – pituitary gland
Slide 3
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
3Fig. 3.1
Changes in Proportions of the Human Body During Growth
Slide 4
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
4
Height and Weight in Infancy and Childhood
Infancy Average 20 inches, 7 ½ lbs at birth
Triple weight by 1 year
½ adult height, 20% adult weight by age 2
Early Childhood
Growth slows, patterns vary individually
Girls slightly smaller and lighter
Girls gain fat, boys gain muscle
Middle and Late Childhood
Slower, consistent growth
Muscle mass and strength increase
Boys stronger, body proportions change
Slide 5
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
5
Body Growth and Change
• Puberty– Period of rapid physical and hormonal changes– Physical changes; growth spurt
• Girls – menarche, hips widen, body hair– Onset for most: 9 to 15 years of age
• Boys – first ejaculation, grow taller, body hair– Onset for most: 10 to 17 years of age
Slide 6
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
6
Body Growth and Change
• Puberty– Hormonal changes
• Powerful chemicals from endocrine glands• Hypothalamus – eating and sexual behavior• Pituitary gland – controls growth, regulates glands• Gonads – male testes, female ovaries• Gonadotropins – stimulate testes, ovaries
Slide 7
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
7
Body Growth and Change
• Puberty– Hormones increase dramatically in adolescence
• Testosterone – voice change, genital growth– Dominates male changes
• Estradiol – estrogen for breast growth– Dominates female changes
– Onset affects social competence– Behaviors and moods can affect hormones
Slide 8
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
8
Body Growth and Change
• Psychological effects of puberty, onset timing– Early maturation
• Boys: positive self-image, better peer relations• Girls: similar to boys, not as strong, at more risk of
behavior problems
– Late maturation• Boys: developed stronger positive self-image in their 30s
Slide 9
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
9
Body Growth and Change
• Early adulthood– Height is constant– Many reach peak of muscle tone and strength in
late teens and twenties– Peak in joint functions in twenties– Decline in the thirties
Slide 10
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
10
Body Growth and Change
• Middle adulthood– Physical appearance
• Loss of height (more for women), weight gain• Skin wrinkles, sagging, aging spots appear in 40s or 50s• Hair thins and grays, fingernails and toenails thicken• Youth-oriented culture affects lifestyle changes• Baby boomers desire plastic surgery, Botox
Slide 11
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
11
Body Growth and Change
• Middle adulthood– Strength, joints, and bones
• Sarcopenia – muscle mass and strength loss• 1% to 2% muscle loss after age 50
– Cardiovascular system and lungs• HDL and LDL cholesterol, clogged arteries • Hypertension: blood pressure increases• Decreased lung capacity after age 55
Slide 12
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
12
Body Growth and Change
• Middle adulthood– Sexuality changes
• Climacteric — fertility declines• Menopause — menstrual periods ceases
– Dramatic decline of estrogen; a negative experience for most women
– Males do not lose fertility
Slide 13
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
13Fig. 3.4
Lung Capacity, Smoking and
Age
Slide 14
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
14
Body Growth and Change
• Late adulthood– Physical appearance more pronounced
• Facial wrinkles, age spots• Weight loss after age 60; decreased by exercise and
weight lifting
– Circulatory system• Increased blood pressure, linked to chronic conditions
and longevity
Slide 15
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
15
The Brain
• Brain physiology– Structure and function
• Forebrain• Cerebral cortex has four lobes
– Frontal, occipital, temporal, parietal lobes• Deeper in brain:
– Hypothalamus, pituitary gland, amygdala, hippocampus
Slide 16
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
16Fig. 3.6
The Brain’s Four
Lobes
Slide 17
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
17
Functions of Lobes of the Cortex
Frontal Involved in voluntary movement, thinking, personality, and intentionality or purpose
Occipital Function in vision
Parietal Active role in hearing, language processing, and memory
Temporal Roles in registering spatial location, attention, and motor control
Slide 18
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
18
The Brain
• Brain physiology– Neurons — nerve cells handling information
processing at the cellular level• Axon, dendrites, synapses • Neurotransmitters: dopamine• Myelin sheath and myelination• Neural circuits
– Lateralization — specialization of functions in one hemisphere of cerebral cortex
Slide 19
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
19
The Neuron
Fig. 3.7
Slide 20
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
20
The Brain
• Infancy– Shaken Baby Syndrome– Born with about 100 billion neurons– Brain flexibility and resilience demonstrated in
deprived environments– Dramatic increases of neural connections– Brain areas do not mature uniformly; skills affected
by myelination and interconnections
Slide 21
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
21
The Brain
• Infancy– Myelination; visual and auditory– Rapid growth of myelin sheath, dendrite and
synapse connections– Blooming and pruning of connections in brain– At birth, greater activity in left hemisphere– Motor control begins about 2 months
Slide 22
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
22
Dendritic Spreading
Fig. 3.12
Slide 23
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
23
The Brain
• Childhood– The brain and head grow more rapidly than any
other part of the body — growth curves– Some brain size increase due myelination and
number and size of dendrites– Greatest anatomical brain increases from ages 3
to 15 years; distinct bursts of growth
Slide 24
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
24Fig. 3.13
Synaptic Density in
Human Brain from Infancy to Adulthood
Slide 25
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
25
The Brain
• Childhood– Ages 3 to 6; most rapid growth in frontal lobe– Age 6 to puberty; most dramatic growth in
temporal and parietal lobes• Promotes spatial relations and language
– Brain pathways and circuitry promote cognitive control (attention, thoughts, actions, choices)
Slide 26
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
26
Growth Curves for Head and Brain and for Height and Weight
Fig. 3.14
Slide 27
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
27
The Brain
• Adolescence– Brain continues growth
• Corpus callosum – axon fibers thicken• Prefrontal cortex – increased reasoning, decision
making, self-control• Amygdala – seat of emotions, matures earlier
– Positive link between volume and duration of aggressive behavior toward parents
Slide 28
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
28
The Brain
• Adolescence– Research on brain development and changes
• Thicker prefrontal cortex, more brain connections linked to peer pressure resistance
• Early ‘turbo charged’ emotions – more risky behaviors, drug use, legal system involvement?
• Brain change – result of biology, experiences
Slide 29
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
29
The Brain
• Adulthood and aging– Brain loss: 5-10% of weight in ages 20 to 90– Dendrites decrease; myelin sheath damage– Shrinkage is not uniform; most in prefrontal cortex – General slowing of brain and spinal cord function
• Begins in middle age, accelerates with age
– Reductions in neurotransmitters
Slide 30
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
30
The Brain
• The adapting brain– Exercise and activities influence development– Remarkable repair capability
• Neurogenesis – new cells generated• Dendrite growth; “rewiring” to compensate loss• Less lateralization with age, more adaptation
– Results of the Nun Study
Slide 31
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
31
Sleep
• Infancy – sleep/wake cycle– Newborns average 16-17 hours a day– Varied patterns; longest period is 11 pm to 7 am
• At 1 month – infants sleep more• At 6 mos – closer to adult-like sleep patterns• Most common problem – night waking• Culture affects sleep patterns
Slide 32
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
32
Sleep in Infancy
• Varied sleeping patterns– Longest sleep period: 11 pm to 7 am– May change from longer to shorter sleep periods– Most close to adult patterns by 4 months
• More REM sleep than any other time of life
• Shared sleeping with parents is controversial
Sleep
Slide 33
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
33
Sleep
• REM sleep– As infant, half of sleep pattern; begins sleep cycle
• May provide self-stimulation• Cannot determine if infants dream like adults
– As adult, REM is 20% of sleep pattern; onset 1 hour after non-REM
• Shared sleeping – controversial issue– Common outside United States and Great Britain
Slide 34
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
34
Sleep Across the Human Life Span
Fig. 3.19
Slide 35
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
35
Sleep
• SIDS– Infants stop breathing; most die suddenly in night– Highest cause of infant death in United States– Highest risk: ages 2 to 4 months– Best prevention: infant sleeps on its back (prone)
Slide 36
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
36
Sleep
• SIDS– Risk factors:
• No pacifier, soft bedding, no fan in room • Low-birth weight, sleep apnea, lower SES• Sleeping on stomach or side• Passive exposure to cigarette smoke • Another sibling died of SIDS, abnormal brain stem
functioning• Higher for African American, Eskimo infants
Slide 37
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
37
Sleep
• Childhood– Recommended: 11 to 13 hours each night– Sleep problems
• Inadequate sleep linked to depression, school problems, disagreeable families, living in unsafe neighborhoods, father in poor health
• Uninterrupted sleep and consistent patterns important – linked to behavioral problems
• Nightmares and night terrors
Slide 38
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
38
Sleep
• Adolescence– Inadequate sleep patterns (less than 8 hrs a day)
• Linked to fatigue, moodiness, depression, more caffeine beverage use, falling asleep in school
– Sleep was 9½ hours when given the opportunity– Sleep debt: try to make up lost sleep on weekend– Biological clock and hormone melatonin cause
later waking and going to sleep• Starting school later would decrease absences
Slide 39
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
39
Sleep
• Adolescence– Sleep deprivation and school performance
• More reported illnesses and absences• More depressed, lower self-esteem• Ineffective stress management• Less exercise, unhealthy diet• Grogginess, less attentive, poor test scores• Discipline problems
Slide 40
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
40
Sleep
• Adulthood and aging– Many are sleep deprived (less than 7 hrs a day)
• Work, school, social, or family obligations
– Many adults don’t get enough sleep– Middle age may bring sleep problems
• Wakeful periods at night, less deep sleep
– Many older adults go to bed and wake up earlier,– Insomnia increases in late adulthood
Slide 41
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
41
Longevity
• Life span — upper boundary of life, maximum number of years an individual can live; about 120 years of age
• Life expectancy — number of years that an average person born in a particular year will probably live
Slide 42
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
42
Longevity
• Life expectancy– Highest in Japan – 81 years– Racial differences in the U.S.
• Highest for Whites – 78 years– White females – 81 years
• Females have higher expectancy than males– Begins in mid-30s, gap increases with age– Male lifestyle associated with more risks, biological
factors
Slide 43
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
43
Longevity
• Centenarians– Numbers increasing
• More women than men; health keeps improving
– Influenced by• Biology, heredity, family history, coping ability• Health (weight, diet, smoking, exercise)• Education, personality, lifestyle
– Highest ratio in Okinawa
Slide 44
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
44Fig. 3.22
Risks of Dying from Cancer in
Okinawa, Japan, and the United States
Slide 45
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
45
Longevity
• Biological theories of aging– Four major theories– No consensus on which best explains aging
Slide 46
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
46
Biological Theories of Aging
Cellular Clock Theory
Maximum times that human cells can divide is about 75 to 80
Free-Radical Theory
People age due to cells’ metabolism produces unstable oxygen molecules (free radicals)
MitochondrialTheory
Aging caused by decay of mitochondria; oxidative damage
Hormonal Stress Theory
Aging in body’s hormonal system can lower resistance to stress and increase risks of disease
Slide 47
© 2010 The McGraw-Hill Companies, Inc. All rights reserved.
47
The End