Which body system is evaluated by spirometry?

• A. Digestive
• B. Nervous
• C. Respiratory
• D. Circulatory

Answer: (C)

Spirometry is a lung function test that measures how air moves into and out of the lungs and how quickly it happens. This directly assesses the respiratory system—the lungs and airways—by providing values that show how well airflow is moving and how much air the lungs can hold, which helps identify issues like obstruction or restriction.

The other body systems aren’t evaluated by this test. The digestive system handles breaking down and absorbing nutrients, the nervous system controls and coordinates body functions, and the circulatory system moves blood and oxygen through the body. Spirometry focuses on lung function, so the respiratory system is the one being evaluated.