Question

Explain how do we breathe? [5 MARKS]

Answer 1

Each point: 1 Mark
1. We take in air through our nostrils. When we inhale, air passes through nostrils into nasal cavity which reaches the lungs through windpipes.
2. The chest cavity where the lungs are present is surrounded by ribs on the sides and diaphragm forms the base.
3. Breathing involves the movement of the diaphragm and the rib cage.
4. During inhalation, ribs move up and diaphragm moves down to increase the chest cavity space. Lungs get filled with air.
5. During exhalation, ribs move down and diaphragm moves up to its former position. Thus reduces chest cavity space and air is pushed out.