Which are expected physiological change(s) in the respiratory system of an older adult? (Select all that apply)

Choice A reason: Aging leads to structural changes in the chest wall and spine, such as kyphosis, which increases the anteroposterior diameter. This "barrel chest" appearance occurs as the thoracic cage becomes less flexible and the lungs lose their ability to fully collapse during the expiration phase. Choice B reason: Vital capacity actually decreases with age due to the loss of lung elasticity and weakened respiratory muscles. The lungs become less compliant, and the residual volume increases, meaning the maximum amount of air an individual can expel after a maximum inhalation is significantly reduced. Choice C reason: The aging process involves the degradation of elastin fibers within the lung parenchyma, leading to decreased elastic recoil. This loss of "snap-back" ability results in smaller airway collapse during expiration, leading to air trapping and a decrease in the efficiency of gas exchange within the alveoli. Choice D reason: With advancing age, the costal cartilages that connect the ribs to the sternum undergo calcification, making the rib cage more rigid. This increased stiffness raises the work of breathing as the respiratory muscles must work harder to expand the less compliant thoracic cavity during inspiration. Choice E reason: Hyperresonance is an expected percussion finding in older adults because of the increased air trapping and anatomical changes associated with decreased lung elasticity. The relative increase in air-to-tissue ratio in the lungs produces a lower-pitched, hollower sound when the chest wall is percussed.