Which aging process impairs the respiratory system and oxygenation

Which aging process impairs the respiratory system and oxygenation?

     Decreased lung tissue elasticity

     Increased number of alveoli

     Increased cough receptor sensitivity

     Increased oxygen retention

The Correct Answer and Explanation is:

Correct Answer: Decreased lung tissue elasticity

Explanation

As the human body ages, various physiological changes occur that can impair the function of the respiratory system and the body’s ability to oxygenate tissues effectively. Among the options listed, decreased lung tissue elasticity is the primary aging-related process that impairs respiratory function and oxygenation.

Lung tissue is made up of elastic fibers that allow the lungs to expand and recoil efficiently during breathing. With aging, these elastic fibers gradually deteriorate, leading to reduced elasticity of lung tissues and alveolar walls. This decline in elasticity causes several problems:

1. Reduced lung compliance – While the chest wall becomes stiffer, the lungs themselves become less elastic, which reduces the efficiency of ventilation.
2. Impaired gas exchange – The reduced elasticity causes air trapping and incomplete emptying of the lungs during exhalation, which lowers the efficiency of gas exchange (oxygen in, carbon dioxide out).
3. Decreased vital capacity and increased residual volume – The amount of air the lungs can move during active breathing decreases, while the amount of air remaining after exhalation increases.
4. V/Q mismatch – Ventilation-perfusion mismatch becomes more common due to less uniform ventilation and perfusion of alveoli, contributing to lowered arterial oxygen levels.

By contrast, the other options do not accurately reflect aging changes that impair respiratory function:

• Increased number of alveoli: This is incorrect; alveolar number does not increase with age—in fact, alveolar surface area may decrease.
• Increased cough receptor sensitivity: Cough reflex sensitivity typically decreases with age, increasing the risk of aspiration.
• Increased oxygen retention: This is incorrect; older adults are more likely to experience decreased oxygenation, not retention.

Therefore, decreased lung tissue elasticity is the most significant age-related change that impairs respiratory function and oxygen delivery.