1. The Journey Of Adulthood, 6/e Helen L. Bee & Barbara R. Bjorklund
Chapter 2
PHYSICAL
CHANGES

2. Primary and Secondary Aging
• Primary aging: aspects of physical changes with age that are universally shared and inevitable, a result of some basic biological process.
• Secondary aging: the part of the changes with age in physical functioning that is not inevitable but may result from widely shared environmental events.
• It is particularly difficult to separate the effects of disease from normal aging.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

3. Theories of Primary Aging
• No single theory can explain all of the changes that occur in primary aging.
Oxidative Damage
Genetic limits
Caloric Restriction
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

4. Theories of Primary Aging
Oxidative Damage
• Free radicals:
• damage DNA.
• cause lipofuscin, build up in cells that is implicated as a cause of numerous diseases.
• are inhibited by antioxidants.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

6. Theories of Primary Aging
Genetic limits
• Each species has a characteristic maximum life span.
• Correlation between the longevity of a species and the number of times its cells will divide.
• Telomeres (lengths of repeating DNA at tips of cells) appear to serve as timekeepers for the organism.
• Genetic limits may be integral part of normal development for some cells.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

7. Theories of Primary Aging
Caloric Restriction
• Promising explanation of aging.
• Age-related differences in number of calories metabolized by the body.
• Dietary restriction shown to increase longevity in lab rats.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

8. Longevity, Life Expectancy, and Life Span
Longevity: average expected length of life at any particular time in history, in a particular culture; has increased significantly in most of the world.
• Life expectancy: refers to the average number of years a person of a given age can still expect to live; has risen dramatically primarily through eradication of most infectious diseases.
• Life span: refers to the upper boundary of years a given species can expect to live. Despite increases in longevity and life expectancy, life span has not shown much change.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

9. Longevity, Life Expectancy, and Life Span
• On average, women live longer than men do.
Some explanations:
1) Women are less likely to inherit sex-linked genetic disorders.
2) Women are naturally protected from some diseases.
3) Women survive difficult conditions better.
4) Women are less likely to participate in high risk behaviors.
5) Women are more likely to have safer jobs.
6) Women engage in more health oriented behaviors.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

10. Physical Changes over Adulthood
Outward Appearances
The Senses
Bones and Muscles
Cardiovascular and Respiratory Systems
Brain and Nervous System
Immune System
Hormonal System
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

11. Physical Changes over Adulthood
Outward Appearances
• Age-related changes height, weight, skin elasticity, and hair color and loss.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

12. Physical Changes over Adulthood
The Senses
Vision
Hearing
Taste and Smell
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

14. Physical Changes over Adulthood
The Senses
Vision
• Vision is the last sense to develop and the first to show signs of aging.
• Lens thickens and yellows.
• Pupil loses ability to open in response to reduced light.
• Lens also loses elasticity interfering with its ability to accommodate.
• Loss of visual acuity (ability to perceive detail in visual patterns).
• Presbyopia (reduced visual acuity) can be corrected with glasses.
• Gradual loss of dark adaptation, with marked decline after age 60.
• Cataracts involve the gradual clouding of the lens of the eye, so that images are no longer transmitted sharply to the retina.
• Glaucoma is a dangerous buildup of pressure inside the eye which can destroy the optic nerve and lead to blindness.
• No gender differences in visual declines.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

16. Physical Changes over Adulthood
The Senses
Hearing
• Hearing loss in higher tones and shortening of the loudness scale.
• Presbycusis
• By age 65, ¼ of adults have some significant hearing impairment, and rates rise sharply with age.
• Men more likely than women to suffer from hearing loss
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

17. Physical Changes over Adulthood
The Senses
Taste and Smell
• Four basic flavors (salty, bitter, sweet, and sour).
• Slight decline for salty and bitter, but nor for sweet and sour.
• Saliva production decreases and this affects taste.
• Changes in smell are more dramatic.
• Olfactory ability peaks between ages 20 and 40.
• Sense of smell drops slightly between ages 40 and 70 and then dramatically after age 70.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

18. Physical Changes over Adulthood
Bones and Muscles
Muscles
• Significant loss of muscle tissue leads to a reduction in physical strength.
• Strength training can prevent this loss.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

19. Physical Changes over Adulthood
Bones and Muscles
Bones
• Bone marrow gradually disappears from the bones of the arms and legs and becomes concentrated in the bones of the trunk.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

20. Physical Changes over Adulthood
Bones and Muscles
Bones
• Calcium is lost from the bones, bone mass is reduced and bones are more brittle and porous.
• Process begins around age 30.
• More pronounced in women than men.
• Osteopenia is moderate bone loss.
• Osteoporosis is severe bone loss (20% of women over 50, 50% over 80).
• Hormone Replacement Therapy (HRT) can prevent the acceleration of bone loss and increases bone mass density.
• Calcium and Vitamin D are also important for maintaining strong bones.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

21. Physical Changes over Adulthood
Bones and Muscles
Bones
• Osteoarthritis occurs more frequently in women, older and overweight people.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

23. Physical Changes over Adulthood
Cardiovascular and Respiratory Systems
• Maximum oxygen uptake reflects the body’s ability to take in and utilize oxygen during exercise. It peaks in adolescence and declines steadily with age. Varies significantly depending on activity level.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

25. Physical Changes over Adulthood
Brain and Nervous System
• Loss of brain cells (neurons) in primary aging is less than previously believed.
• Loss of total number of neurons but not all loss translates to functional decline.
• Life-long plasticity (new dendrites and pruning).
• Slowing of transmission across the synapses between neurons.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

26. Physical Changes over Adulthood
Immune System
• B cells make antibodies which react to infectious agents.
• T cells reject and consume harmful foreign cells.
• B cells show abnormalities with age, accounts for increase of autoimmune disorders.
• With age T cells show reduced abilities to fight new infection.
• Immune function is worsened by psychological stress and depression.
• Nutritional supplements can enhance immune function.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

27. Physical Changes over Adulthood
Hormonal System
• The climacteric is the age-related loss of reproductive ability.
In women:
Menopause occurs signaling an end to reproductive abilities.
Ovarian failure related to drop in estrogen and changes in progesterone.
Average age of menopause is 51.
HRT is commonly used with menopausal and postmenopausal women.
In men:
Gradual decline in testosterone.
Decrease in viable sperm, muscle mass, sexual desire, etc.
Decline in sexual response.
Erectile dysfunction is associated with age and can be treated with medication.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

28. Changes in Physical Behavior
Stamina, Dexterity and Balance
Sleep
Sexual Activity
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

30. Changes in Physical Behavior
Stamina, Dexterity and Balance
• Stamina: ability to sustain moderate or strenuous activity over a period of time. Declines due to changes in the circulatory system and muscles.
• Dexterity: the ability to use the hands or body in a skillful way, is lost as a result of arthritic changes in the joints.
•Balance: the ability to adapt body position to change also declines with age.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

32. Changes in Physical Behavior
Sleep
• Changes in the neurological system increase likelihood of insomnia.
• Some sleep problems are due to health problems and medications.
• Behavior changes can improve sleep (e.g., being active).
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

33. Changes in Physical Behavior
Sexual Activity
• The climacteric is the age-related loss of reproductive ability.
• Frequency of sexual activity drops from the 20s into late adulthood.
• This research is limited by reliance on surveys.
• Factors that affect probability that an older person will have sexual relations:
1) Physical ability
2) Desire
3) Sexual partner
4) Privacy
5) Other forms of sensual activity
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

35. Individual Differences in Primary Aging
• Genetics
• Lifestyle
• Psychosocial Factors
Economics
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.

36. Recurring and Unanswered Questions
How quickly do we age?
How can we disentangle primary and secondary aging?
Why do individuals age at different rates and in different ways?
• Specific experience may affect the rate, or pattern, or physical aging (e.g., exercise).
• Heredity influences aging.
• Primary aging and economics.
The Journey of Adulthood 6/e by Bee & Bjorklund. Copyright © 2007 by Pearson Education. All rights reserved.