Chapter 5The Physical Self

Chapter 5: The Physical Self Genetic and environmental forces e.g.

heightAverage: female 5’4” male 5’9”Can be affected by malnutritionCatch-up growth possible

After illness or periods of malnutritionMore 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 hypothalamusProduces 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 adultGreater loss in sensory-motor areasPlasticity still possible

Main result of age is slower processing

Principles of Growth Procession of growth is orderly

Cephalocaudal: from head, downwardProximodistal: 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 firstEstablish more regularity at 3-6 monthsREM 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 tactAbility to learn from experience and from

consequencesLimited in capacity to move voluntarily Intentionality also limitedCannot 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 moPincer grasp by 6 months

Motor SkillsRhythmic 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 feedbackMotor milestones are learnedAlso require maturationA nature/nurture position

Adolescence

Growth spurt triggered by hormonesPeak 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 laterHeavy & tall/mature earlierRegular strenuous exercise/later

Psychological Implications

Girls become concerned w/appearance Individual reactions vary widelyNegative 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 esteemOlder 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 problemsPoor eating habits, sedentary lifestyle

Leading causes of deathMotor vehicles and violence

Alcohol and drug use, cigarette smokingAlso 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 ageHeart and lung capacityTemperature control Immune system and strengthReserve capacity

On average, older people are less fit than younger BUT not all• Physically active remain fit

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 RTNovel/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 youngerConclusion: 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 functioningSlows bone loss, strengthens musclesLess depression, delays disability

Diseases Common in Old Age

Osteoporosis: Smokers, light frame, at risk Increase calciumWeight-bearing exercise

Osteoarthritis: deterioration of cartilage Successful aging

Both physical and mental functioning Positive attitude