Chapter 3

The Physiology & Pathology of Aging

Objectives:Compare & contrast the concepts of

aging as a “disease” & aging as a “process”.

Compare & contrast preventive medicine & curative medicine.

Describe the theories of biological aging.

Aging Culture not only

influences personal perspectives & family living arrangements but also the way that scientists approach aging and death.

Western medicine, with its greater emphasis on curative rather than preventive medicine.

Paola S. Timiras

Aging Universal process Intrinsic Progressive Deleterious (harmful) Irreversible

Disease Selective process Intrinsic & extrinsic May progress or

regress Occasionally

deleterious Treatable and has a

known cause

Average life expectancy in the United States:

Has risen from 45 years in 1900 to 76 years in 1990: attributed to what?

Yet during this period, there has been no change in the maximum life span potential

(the oldest age reached by an individual in a population) of Americans, est. to be about 115.

Chronic Disease of Aging- Can be modified by behavior changes: p.50

Hypertension Atherosclerotic

cardiovascular disease Cancers COPD Diabetes Mellitus(II) Osteoporosis Osteoarthritis Choleithiasis

Reduce Sodium & body weight

Treatment of hypertension

Stop smoking Reduction of dietary fat Minimization of sun

exposure. Avoidance of alcohol

Condition Prevention

Theories of Biological Aging

1. Molecular & Evolutionary Theories of Aging

2. Cellular Theories of Aging

3. Free-Radical Theory of Aging

4. Cross-Linking & Glycosylation Theories of Aging

Age-Related Changes of the Organ Systems:

Integumentary System Because skin covers

our entire body, it is more noticeable than other age-related changes.

It begins to flatten, becomes thin and wrinkling.

Integumentary System

Chronic exposure to sunlight is the biggest source of aging skin.

Responsible for wrinkling, yellowing, coarseness, & irregular pigmentation of skin with advancing years.

Skin Cancer

Malignant melanoma Basal cell carcinoma Squamous cell

carcinoma Basal cell & Squamous

comprise more than 50 % of all malignancies in the U.S.

Nervous System

The nervous system must be intact for proper functioning of all the other systems.

Because of its complexity, it is the least understood.

Yet, central nervous system disorders are the most common cause of disability in the elderly.

Normal / Abnormal memory loss with aging

Dementia Mental deterioration

in orientation, memory, intellect, judgment and emotional status

Two thirds of all nursing home patients suffer from dementia

Alzheimer’s The most common form of

dementia. As the disease

progresses, all of the deficits of dementia worsen.

Patients usually regress developmentally, displaying some behaviors similar to infants.

Special Senses: Vision Hearing Taste Smell

Sleep

Musculoskeletal System

Skeletal muscle undergoes changes as we age.

Osteoporosis: the reduction in bone mass & bone density-condition predisposes an individual to fractures,-vertebras-femur-distal radius.

Osteoarthritis: degenerative joint disease-second most common cause of disability in the U.S.-affecting >50 million Americans.

Cardiovascular System Postural Hypotension: a fall in

systemic blood pressure upon rising from a supine to a standing position. Causes lightheadedness when a person stands up & can thus increase the risk of falling.

Atherosclerosis: development of fatty plaques & the proliferation of connective tissue in the walls of arteries-can lead to blockage of the artery.

Cardiovascular -continued Aneurysms--destruction of the inner layers of the

artery wall can weaken it & cause it to balloon out under the force of blood pressure.

Breaks in the fibrous capsule of fatty plaques can cause ulcerations, leaving the underlying fat deposits exposed to the bloodstream, which clump & form clots or thrombus.

Atherosclerosis Development of fatty

plaques and the proliferation of connective tissue in the walls of the arteries.

Respiratory System: Chronic obstructive

pulmonary disease (COPD), & lung cancer (caused primarily by cigarette smoking)

Steps leading to emphysema begin when cigarette smoke irritates the respiratory tract, stimulating proliferation of white blood cells called macrophages.

Chronic bronchitis-common in elderly- those with a long history of cigarette smoking.

Hematological System

High prevalence of anemia.

Pernicious anemia - Vitamin B-12.

Red cells are many times decreased.

Immune System:

Infections Cancer Autoimmune

disease

Genitourinary & Endocrine Systems:

Kidneys & bladder Pituitary Gland Thyroid Gland Adrenal Gland Testes & Ovaries

Summary:

While there may be wisdom in the adage, “live for the day”, it is equally wise, from a health perspective, to “live for tomorrow”.

“A word to the wise is sufficient!”