Aging Effects – Part 08

During the aging process, the elasticity of tissues deteriorates throughout the body, including the lungs which no longer have the resilience or vital capacity, causing an increase in breathing difficulties in the elderly.By age 50, vital lung capacity has decreased to 65% and to 40% by age 70 of original capacity.Movements of the chest cage are often restricted because of arthritic changes in the rib articulations and by a decreased flexibility at the costal cartilages. This reduction in resilience restricts ventilation, limiting exercise performance and capabilities.Some emphysema occurs in the aged, but this varies depending on their lifetime exposure to cigarette smoke or other respiratory irritants. Comparative studies done on smokers and nonsmokers clearly show the negative effects of smoking on respiratory performance.

With age-related structural changes, the number of alveoli (air sacs) diminishes. Chronic alveolar hypoxia (low oxygen) from such diseases as emphysema or chronic bronchitis may lead to pulmonary hypertension (high blood pressure in the arteries of the lungs), which, in turn, overworks the right ventricle of the heart.

Systemic hypertension often weakens the left ventricle, leading to congestive heart failure (CHF) and pulmonary edema in which excess tissue fluid collects in the alveoli decreases gas exchange.

Many of the protective mechanisms of the respiratory system decline with age. The ciliary activity of the mucosa decreases and the phagocytes in the lungs become less effective. As a result, the elderly are more prone to respiratory infections, especially pneumonia.