Image Based Question – 65205

This apparatus which is used by the patient can demonstrate and measure all of the following except

A. Tidal volume

B. Residual volume

C. Vital capacity

D. Inspiratory reserve capacity

Show Answer

Correct Answer » B Explanation

Ans. is ‘B’ i.e., Residual Volume (RV)

This apparatus is Spirometry and it cannot measure Residual Volume (RV)

Spirometry:

• Pulmonary ventilation can be studied by recording the volume movement of air into and out of the lungs, a

• method called spirometry.

• Spirogram indicates changes in lung volume under different conditions of breathing.

• It consists of a drum inverted over a chamber of water, with the drum counterbalanced by a weight.

• In the drum is a breathing gas, usually air or oxygen; a tube connects the mouth to the gas chamber.

• When one breathes into and out of the chamber, the drum rises and falls, and an appropriate recording is made on a moving sheet of paper.

Spirometry can measure:-

• Tidal volume (TV)

• Inspiratory reserve volume (IRV)

• Expiratory reserve volume (ERV)

• Vital capacity (VC)

• Forced vital capacity (FVC)/ Forced Expiratory Volume in one second (FEV1)

Spirometry cannot measure:-

• Residual Volume (RV)

• Functional Residual Capacity (FRC)

• Total Lung Capacity (TLC)