Question

What do you understand by inhalation and exhalation? How are they different from each other?

Answer 1

The physical process, by which the air containing oxygen is drawn into the lungs and air containing carbon dioxide is forced out from the lungs are called breathing. Breathing involves two steps, inhalation (inspiration) and exhalation (expiration).

Inhalation (Inspiration)

1. Ribs move upwards and outwards.
2. The diaphragm is pushed downwards and flattens.
3. The volume of the chest cavity increases.
4. Lungs expand, air pressure becomes low.
5. Atmospheric air at higher pressure rushes into the lungs

Exhalation (Expiration)

1. Ribs move downwards and inward.
2. The diaphragm moves upwards and becomes dome-shaped.
3. The volume of the chest cavity decreases.
4. Lung size reduces, air pressure becomes high.
5. Air rushes out of lungs as atmospheric air pressure is lower.