Transcript life-span development

A Topical Approach to
Life-Span Development 6e
John W. Santrock
Chapter 3:
Physical Development
and Biological Aging
Patterns of body growth
• Cephalocaudal pattern =
• Proximodistal pattern =
• Growth rate affected by :
Figure 3.1 - Changes in Proportions of
the Human Body During Growth
Fractions = head size as fraction of total body length
Height and Weight
in Infancy and Childhood
Average ___ inches, ____ lbs at birth
Infancy
Triple weight by ___ year
By age ___, reach ½ adult height, 1/5 adult weight
Early
Childhood
Growth _____, trunk __________, body fat __________;
patterns vary individually
Girls slightly _________ and __________ than boys
Girls have more ______ tissue, boys more __________
Slower, consistent growth
Middle and
Late Childhood Muscle mass and strength _________; bones _______
Body proportions change; boys stronger
Puberty: Physical growth & change
• Puberty =
• Growth spurt
– Order for girls:
• Age of onset:
– Order for boys:
• Age of onset:
Puberty: Hormonal Changes
• Hormones =
Endocrine glands & functions
• Hypothalamus –
• Pituitary gland –
• Gonads =
– Gonadotropins =
Endocrine glands  pubertal changes
Puberty: Hormonal effects
• Hormones increase dramatically
– Testosterone 
– Estradiol 
• Puberty onset affects social competence
• Behaviors and moods can affect hormones
Timing of puberty: Psychological effects
• Early maturation
– Boys:
– Girls:
• Late maturation
– Boys:
– Girls:
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Physical Changes: Early adulthood
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Height
Muscle tone, strength
Joint functions
Elasticity
Middle adulthood: Physical Changes
• 40s-50s
• Declines:
• Increases:
Middle adulthood: Body Changes
• Strength, joints, and bones
Middle adulthood: Body Changes
• Cardiovascular system
• Lungs
Middle adulthood: Sexuality changes
• Climacteric —
• Menopause —
Physical Changes: Late adulthood
• Physical appearance
• Circulatory system
Figure 3.6 - The Brain’s Four Lobes
Functions of Cortical Lobes
Frontal
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• Motor cortex:
Parietal
• Somatosensory cortex:
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Occipital
• Visual cortex:
Temporal • Auditory cortex:
•
Brain Physiology: Neurons
• Neurons: Nerve cells that…
Figure 3.7 - The Neuron
Neuron Structures & Functions
• Dendrites, cell body, axon
• Myelin sheath and myelination
• Neurotransmitters
• Synapse
Neural circuits = groups of specialized neurons
Neural Growth in Infancy
• Born with about __________ neurons
• Rapid growth of:
Figure 3.12 - Dendritic Spreading
The Brain in Infancy
• Skills affected by:
• Blooming & pruning of:
• Brain areas do not mature uniformly
– Rapid growth of:
– Motor control begins at about:
Figure 3.13 - Synaptic Density in Human
Brain from Infancy to Adulthood
The Brain in Childhood
• Brain and head continue to grow more rapidly than
any other part of the body (See Fig. 3.13)
• Greatest anatomical brain increases from ages:
Figure 3.14 - Growth Curves for Head and
Brain and for Height and Weight
The Brain in Childhood
• Age 3 – 6: most rapid growth in:
• Age 6 – puberty: most growth in:
The Brain in Adolescence
Growth in:
• Corpus callosum –
• Amygdala –
• Prefrontal cortex –
The Brain in Adulthood
• General slowing of which functions?
– Begins in middle age, accelerates with age
• Brain loses _____% of weight from age 20 - 90
– Shrinkage is not uniform; most in:
The Brain Can Adapt!
• How can we maintain functions & slow decline?
• Remarkable repair capability
– Neurogenesis: