Chapter 3 - Physical Changes Across Adulthood

Aging

Genes count off years after maturity just as “development” genes lead to maturity

Metabolic Theories

Limited energy in lifetime suggest reducing metabolism will lengthen the lifespan; calorie reduction is associated with longer lifespan

Cellular Theories

Limited number of times a cell can divide, cross-link; evidence is growing tha antioxidants postpone the appearance of age-related diseases

Telomeres

Tips of the chromosomes that shorten with each cell replication

Telomerase

An enzyme needed in DNA replication to fully reproduce the telomeres when cells divide

Free Radicals

Highly reactive chemicals produced randomly in normal metabolism

Cross-linking

Random interaction between proteins that produce molecules that make the body stiffer

Antioxidants

Molecules that stabilize free radicals to become less reactive

Programmed Cell Death Theories

Aging is programmed into genetic code; cells are pre-programmed to self-destruct; the ability of dying cells to trigger key processes in other cells, all of which are also thought to be influenced by external environmental factors

What are the 3 general approaches to slowing/reversing the aging process?

1) Delay the chronic illnesses of old age

2) Slow the fundamental processes of aging to increase lifespan

3) Arrest or reverse aging by removing the damage caused by metabolic processes

Autoimmune Theory

Aging due to faulty immune functioning; decrease in combating bacteria/viruses

What are the 4 steps of wrinkly skin?

1) The outer layer of skin becomes thinner through cell loss, causing the skin to become more fragile.

2) The collagen fibers that make up the connective tissue lose much of their flexibility, making the skin less able to regain its shape after a pinch.

3) Elastin fibers in the middle layer of skin lose their ability to keep the skin stretched out, resulting in sagging.

4) The underlying layer of fat, which helps provide padding to smooth out the contours, diminishes.

Age Spots

Areas of pigmentation that look like freckles

Changes in Hair with Age

Caused by destruction of germ centers that produce hair follicles; cryaing caused by cessation of pigment production

Changes in Body Build with Age

Decrease in height b/w mid-50s and mid-70s

Ex. Women lose 2 inches; men lose 1 inch

What is the percentage of strength loss in the muscles of a 70-year-old?

20%

What is the percentage of strength loss in muscles of an 80-year-old?

40%

Osteroporosis

Leading cause of broken bones in older women

What is the process of bone structure loss in aging?

Loss begins in the late 30s → Loss accelerates in the 50s → Loss slows in the 70s

Body Mass Index (BMI)

< 18.5 BMI

Underweight

18.5-24.9 BMI

Normal

25.0-29.9 BMI

Overweight

> 30.0 BMI

Obese

> 40.0 BMI

Morbidly obese

Apple-shaped Body

More weight around waist

Pear-shaped Body

More weight around hips

What waist-to-hip ratio determines a woman to be abdominally obese?

Above 0.85

What waist-to-hip ratio determines a man to be abdominally obese?

Above 0.90

Cataracts

Clouding that develops in the lens; images cannot be focused clearly on the retina

Glaucoma

Changes in the pressure created by build-up of fluid in the eye; loss of peripheral vision

Presbyopia

The normative age-related loss of the ability to focus on nearby objects, usually resulting in the need for corrective lenses

Macular Degeneration

Leading cause of blindness; destruction of the macula

Diabetic Retinopathy

Involves fluid retention in the macula, detachment of the retina, hemorrhage, and aneurysms; most common cause of blindness among younger and middle-aged people

What are the psychological effects of visual changes?

1) Loss of activities

2) Changes in personality

3) Increase in vulnerability to falls

4) Corrective actions (glasses, surgery)

Aerobic Capacity

Maximum amount of oxygen that can be delivered through the blood

Cardia Output

Amount of blood that the heart pumps per minute

What is erectile dysfunction strongly linked to?

Emotional and physical well-being; life satisfaction

Chronic Obstructive Pulmonary Disease (COPD)

A family of age-related lung diseases that block the passage of air and cause abnormalities inside the lungs

Emphysema

Most serious form of COPD characterized by the destruction of the membranes around the air sacs in the lungs

Chronic Bronchitis

A form of COPD, can occur at any age, but it is more common in people over age 45, especially among people who are exposed to high concentrations of dust, irritating fumes, and air pollution