The correct option is Spirometer.
Explanation
Respiratory volumes and capacities refer to the specific amounts of air inhaled, exhaled, and stored within the lungs during various phases of the breathing cycle. Measuring these volumes is crucial for assessing pulmonary function and diagnosing respiratory disorders.
Option Analysis:
- Spirometer Spirometer: This is the correct instrument used to measure the volume of air inspired and expired by the lungs. It produces a spirogram, which helps in the clinical assessment of pulmonary functions such as Tidal Volume, Inspiratory Reserve Volume, and Vital Capacity.
- Respirometer Respirometer: This device is generally used to measure the rate of respiration (often by tracking oxygen consumption) in living organisms, rather than the physical volume of air moved by the lungs.
- Stethoscope Stethoscope: This is an acoustic device used for auscultation (listening) to internal body sounds, such as heartbeats and breath sounds, but it does not quantify air volumes.
- Sphygmomanometer Sphygmomanometer: This instrument is used to measure arterial blood pressure.
Key Takeaway: A spirometer is the specific apparatus used to measure respiratory volumes and capacities to evaluate lung function.