Pressure gradient between the lungs and atmosphere is maintained by
(1)diaphragm

(2)external intercostal muscles

(3)internal intercostal muscles

(4)All of these

The volume of air involved in breathing movements can be estimated by using
1. ECG
2. Sphygmomanometer
3. spirometer
4. Barometer

Which of the following events happen when air enters lungs
1. Ribs and sternum raised
2. volume of thorax increased
3. Diaphragm contracted
4. All of the above

Which of the following events happen when air expelled from lungs
1. Ribs and sternum returned to original position
2. volume of thorax decreased
3. Diaphragm relaxed and arched upwards
4. All of the above

On an average, a healthy human breathes ______times/minute.
1. 70-72
2. 20-25
3. 12-16
4. 120-80

The volume of air expired forcefully after normal inspiration
1. TV+ IRV
2.TV+ERV
3.TV
4. None of these

The volume of air expired forcefully after forceful inspiration
(1)TV+ IRV

(2)TV+ERV+IRV

(3)TV+ERV+IRV+RV

(4)None of these

The partial pressure of CO₂ is minimum in the

1. atmospheric air

2. Alveoli

3. Deoxygenated blood

4. Oxygenated blood

Diffusion membrane consists of

1. Squamous epithelium of alveoli

2. endothelium of alveolar capillaries

3. Basement substance between them

4. All of the above

A curve obtained when percentage saturation of Hb with O₂ is plotted against the pO₂ is also called as

1. Association curve

2. Dissociation Curve

3. Sigmoid Curve

4. Both 2 and 3