Question
Consider the following statements regarding respiratory function in old age:
I. There is increasing ventilation-perfusion mismatch
II. There is increased ventilatory response to hypoxia and hypercapnia
III. There is a decline in maximum oxygen uptake leading to reduction in cardiorespiratory reserve
IV. There is decline in the Forced Expiratory Volume to Forced Vital Capacity ratio (FEV1/FVC) by around 0·2% per year after the forties
Which of the statements given above are correct?
| A. |
I, II and III
|
| B. |
I, II and IV
|
| C. |
II, III and IV
|
| D. |
I, III and IV
|
Show Answer
|
Correct Answer � D
Explanation
|
|
Respiratory physiology changes with aging:
-
Ventilation–perfusion (V/Q) mismatch increases with age due to:
-
Ventilatory response to hypoxia and hypercapnia decreases, not increases, in older adults. This is due to reduced sensitivity of peripheral and central chemoreceptors.
→ Statement II is incorrect
-
Maximum oxygen uptake (VO₂ max) declines with age because of decreased cardiac output and reduced muscle oxidative capacity, leading to a reduction in cardiorespiratory reserve.
→ Statement III is correct
-
FEV₁/FVC ratio declines by about 0.2% per year after the age of 40, reflecting gradual loss of elastic recoil and small airway closure.
→ Statement IV is correct
