Final answer:
The false statement is that vital capacity increases with age; in reality, it decreases due to reduced lung compliance and increased stiffness of lung tissues.
Step-by-step explanation:
The question centers on the physiological changes in the respiratory system due to aging. The false statement among the options provided is b. Vital capacity increases. As individuals age, the lungs lose elastic tissue, vital capacity decreases due to the lungs becoming stiffer and less pliable, not more. Moreover, lung compliance does indeed change, it usually decreases with age as the lung tissue becomes less flexible. Contrary to option d, the costal cartilages do not become more flexible but rather more rigid, contributing to decreased chest wall compliance. Lastly, respiratory muscles, like other muscles in the body, tend to weaken with age.
Breathing and gas exchange efficiency can be compromised by these age-related changes in lung and chest wall compliance as well as increased airway resistance. Diseases such as fibrosis and emphysema highlight how changes in these properties can significantly impact breathing. An increase in lung resistance or a decrease in compliance leads to difficulty in breathing and potential trapping of air in the lungs.