You probably don’t pay much attention to your breath­ing unless you’re gasping for breath after exercise— or you’re an older adult. Older adults tend to notice their breathing a great deal more. Why? With increas­ing age, the rib cage and the air passageways become stiffer, making it harder to breathe. The lungs change in appearance over time, going gradually from their youthful pinkish color to a dreary gray, caused mainly by breathing in carbon particles (from air pollution). The maximum amount of air we can take into the lungs in a single breath begins to decline in the 20s, decreasing by 40% by age 85. And the rate at which we can exchange oxygen for carbon dioxide drops significantly as the membranes of the air sacs in the lungs deteriorate (Pride, 2005).

One of the difficulties in understanding age-related changes in the respiratory system is that it is hard to know how much of the change is caused specifically by normative developmental factors and how much is caused by environmental factors. For example, it is difficult to determine how much age-related change in respiratory function is due to air pollution.

Respiratory Diseases. The most common and incapac­itating respiratory disorder in older adults is chronic obstructive pulmonary disease (COPD), a fam­ily of diseases that includes chronic bronchitis and emphysema. By 2005, COPD was the fourth leading cause of death in the United States, with rates higher in women than in men. Smoking is the most impor­tant cause of COPD, but secondhand smoke, air pollution, and industrial dusts and chemicals can also cause it (American Lung Association, 2008).

Emphysema is the most serious type of COPD and is characterized by the destruction of the mem­branes around the air sacs in the lungs (American Lung Association, 2008). This irreversible destruc­tion creates holes in the lung, drastically reducing the ability to exchange oxygen and carbon dioxide. To make matters worse, the bronchial tubes col­lapse prematurely when the person exhales, thereby preventing the lungs from emptying completely.

90 CHAPTER 3

Emphysema is a very debilitating disease. In its later stages, even the smallest physical exertion causes a struggle for air. People with emphysema may have such poorly oxygenated blood that they become confused and disoriented. About 95% of the cases of emphysema are self-induced by smok­ing; the remaining cases are caused by a genetic deficiency of a protein known as an a^antitrypsin (American Lung Association, 2008). This protein, a natural “lung protector" is made by the liver; when it is missing, emphysema is inevitable. Although some drugs are available to help ease breathing, lung transplantation remains a treatment of last resort for people with emphysema, especially in the genetic form of the disease.

Chronic bronchitis 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. Treatment usually consists of medication (called bronchodilators) to open bronchial passages and a change of work environment. Similarly, asthma is another very common respiratory disease that is increasing in prevalence. Treatment for asthma also involves the use of bronchodilators.

Overall, treatment for COPD needs to begin as soon as a problem is diagnosed. That may involve stopping smoking (the best treatment available for smokers). In other cases, supplemental oxygen or using glucocorticosteroid medications may provide some relief. The thing to remember, though, is that the damage caused by COPD is irreversible.

Concept Check

1. What are the major age-related changes in the cardiovascular system?

2. What are the major age-related changes in the respiratory system?