Which of the following is a normal physiological change in the elderly?

The rationale behind selecting diminished renal, cardiac, and lung function as a normal physiological change in the elderly lies in the natural aging process. As individuals grow older, their organs and systems undergo various changes that can lead to a decline in function.

For the renal system, age can lead to a decreased glomerular filtration rate, meaning the kidneys become less efficient at filtering waste from the blood. Cardiac function typically experiences changes in the heart's structure and function, often resulting in a reduced ability to pump blood effectively. Similarly, the lungs may experience decreased elasticity, reduced respiratory muscle strength, and overall diminished lung function, leading to a decreased capacity for physical activity and a potentially higher risk for respiratory illnesses.

Understanding these changes is vital for healthcare providers and can influence how medical care is administered to elderly patients, including monitoring for conditions such as heart disease or chronic kidney disease. Other options, such as increased lung capacity, a stronger immune response, or improved cognitive function, do not reflect the typical physiological adaptations seen with aging, making the chosen answer not only the most accurate but also relevant for comprehension of elderly health care management.