chapter 5 the physical self. chapter 5: the physical self genetic and environmental forces e.g....
TRANSCRIPT
Chapter 5: The Physical Self• Genetic and environmental forces e.g.
height– Average: female 5’4” male 5’9”
– Can be affected by malnutrition
– Catch-up growth possible• After illness or periods of malnutrition
– More short people in cold climates• Smaller body surface for heat loss
The Endocrine System• Glands that secrete hormones• Pituitary gland: the master gland
– Controls all other glands– Is controlled by the hypothalamus– Produces growth hormone
• Testes secrete androgens like testosterone
• Ovaries secrete estrogen and progesterone
Plasticity• Responsiveness to experiences
– Can be negative• Vulnerable to damage• Environmental deprivation
– Can be positive• Aids in recovery from from injury• Can compensate for each other• Can benefit from stimulation• Allows for adaptability
Brain Development 2• Critical period: late prenatal & early
infancy
• Lateralization (at birth)– Left hemisphere
• Analytic reasoning, language
– Right hemisphere• Understanding spatial information• Visual-motor information
– Corpus callosum connects the two
Brain Development 3• Never truly complete
– Changes occur across lifespan
• Growth spurts in infancy, childhood and adolescence
• Full adult weight by about age 16
• Processing speed increases in adolescence
• Myelination continues into adulthood
Brain Development 4• The Aging Brain
– Gradual and mild degeneration
• Elderly adults– 5-30% fewer neurons than younger adult– Greater loss in sensory-motor areas– Plasticity still possible
• Main result of age is slower processing
Principles of Growth• Procession of growth is orderly
– Cephalocaudal: from head, downward– Proximodistal: from the center, outwards – Orthogenic: from global, undifferentiated
to specialized
A Life-Span Developmental Model of Health
• Health: A life-long process
• Determined by both genetic and environmental factors
• Is multi-dimensional: well-being, illness
• Changes involve both gains and losses
• Sociohistorical context: SES
The Infant• Typically 7 to 71/2 lbs., 20 inches long• Period of rapid growth• Neonatal reflexes (see Table 5.3 in text)
– Survival reflexes: clearly adaptive• Breathing, eye-blink,sucking/rooting
– Primitive reflexes: less adaptive• Typically disappear by 4 months
– Babinski: toes fan– Grasping
• Used diagnostically
The Infant 2• Behavioral States
– Short sleep-wake cycles at first– Establish more regularity at 3-6 months– REM sleep
• 50% of the time for newborns• 25-30% by 6 months
– May be useful for reducing stimulation– Individuality in infant patterns
The Infant 3• Strengths and weaknesses
– Sensory system in tact– Ability to learn from experience and from
consequences– Limited in capacity to move voluntarily– Intentionality also limited
– Cannot interpret complex stimuli
Infant Physical Behavior• Developmental norms (see Table 5.5 )
– Average age of mastery
• Gross before fine motor skills• Crawling at 7–10 months• Walking at about 1 year• Study of “walkers” (Siegel & Burton, 1999)
– Infants not using walkers sat up, crawled, and walked earlier
– Need sensory feedback I.e.,to see feet
Physical Behavior 2• Manipulating Objects
– Grasping reflex disappears: 2-4 mo– Pincer grasp by 6 months
• Motor Skills– Rhythmic Stereotypies
• Rocking, bouncing, mouthing objects, banging arms and legs
• Precede a skill then disappear
Dynamic Systems Approach• A self-organizing process
– Trying new movements – Use sensory feedback– Motor milestones are learned– Also require maturation– A nature/nurture position
The Child
• Age 2 until puberty– 2-3 inches in height, 5-6 lbs weight– Bones grow and harden– Run faster, jump higher, and throw a ball
farther– Skills very responsive to practice– Hand-eye coordination, fine motor, and
reaction time all improve
Health and Wellness in Childhood
• Education level of parents a factor
• Nutrition: Well-balanced diet important– High-carb foods detrimental
• Injuries, auto crashes: Leading cause of death
• Exercise: Promotes physical, cognitive, social well-being, academic skill
• Child obesity: Junk-food, TV
Adolescence
• Growth spurt triggered by hormones– Peak in height: Age 12/girls, 14/boys
• Menarche: Average age 12½• Earlier in countries with good nutrition• Maturation different by ethnicity• AA and MA girls earlier than White
• Semenarche: Average age 13• Emission of seminal fluid
Rates of Development• Genes set the process in motion
• Hormones responsible for changes
• Environment also– Secular trend: better nutrition
• Earlier maturation,larger body size
– Poorly nourished/mature later– Heavy & tall/mature earlier– Regular strenuous exercise/later
Psychological Implications
• Girls become concerned w/appearance– Individual reactions vary widely– Negative views about menstruation
• Boys likely to welcome the changes
• Family relations remain important– Distance and conflict with parents
• Usually about only minor issues
Early versus Late Development
• Early males: Advantageous– More positive reactions from others
• Late/males: Disadvantageous– More behavior and adjustment problems
• Early/females: Disadvantageous– Subject of ridicule, lower self esteem– Older peer group = problems
• Late/ females: Academic advantages• Differences tend to fade with time
Physical Behavior
• Dramatic physical growth overall
• Boys continue to improve
• Girls tend to level off or decline– Not totally explained by biology
• Gender role socialization important• Gender performance gap has narrowed• E.g., track, swimming, cycling records
Health and Wellness in Adolescence
• Obesity a continuing problem– Higher risk: Diabetes, heart, BP problems– Poor eating habits, sedentary lifestyle
• Leading causes of death– Motor vehicles and violence
• Alcohol and drug use, cigarette smoking– Also result in risky choices
The Adult
• Minor changes in the 20s & 30s
• Noticeable by the 40s– Wrinkles, gray hair, weight gain
• In the 60s: Weight, muscle, bone loss– Osteoporosis in older women
• Fair, light frame, smokers• Calcium, exercise, (HRT?)
– Osteoarthritis: Joint deterioration
Functioning and Health
• Most systems show decline with age– Heart and lung capacity– Temperature control– Immune system and strength– Reserve capacity
• On average, older people are less fit than younger BUT not all• Physically active remain fit
The Reproductive System
• Beginning in adolescence– Sex hormones influence behavior
• Male testosterone – Levels fluctuate daily
• Female estrogen & progesterone– Monthly cycle– PMS? Expectations vs. hormones– Calcium & Vitamin D helpful
Menopause and Andropause
• Menopause: Estrogen production declines – Age range 45-54– Symptoms: hot flashes, vaginal dryness– Little anxiety, irritability, depression, or other
stereotypes– Exercise and adequate sleep helpful
• Andropause: Decreasing testosterone– Symptoms: Libido, fatigue, erection, and
memory problems
Slowing Down
• Balance difficulty affects the ability to walk, stand, sit, and turn
• Older people with strong muscles and good cardiovascular capacity can walk briskly
• Major change is slowing of the CNS– Increased RT– Novel/complex tasks more difficult
• Physically-fit older people have quicker RT
Disease, Disuse, or Abuse?
• Birren (1963) study of men aged 65-91– Healthy older same as younger– Conclusion: Aging itself has little effect on
physical and psychological functioning
• Disuse: “Use it or loose it!”– Includes mental exercise
• Abuse contributes to decline– Alcohol, high-fat diet, smoking
Health and Wellness in Old Age
• Acute illnesses less common
• Chronic disease more common
• Most 70-yr-olds: At least 1 chronic impairment
• Tremendous variability
• Exercise, nutrition: Lifelong benefits– Improves cardio, respiratory functioning– Slows bone loss, strengthens muscles– Less depression, delays disability