Question

Breathing definition biologyand mention the phases of breathing

Answer 1

Breathing is defined as process of taking in oxygen and giving out carbon dioxide.

• It is a physical process.
• Lungs are the primary organs of the respiratory system.

Phases of Breathing:

The process of breathing (respiration) is divided into two phases:

1. Inspiration (Inhalation)
2. Expiration (Exhalation)

1. During inspiration, the diaphragm contracts and pulls downward while the muscles between the ribs contract and pull upward.
2. During expiration, the diaphragm relaxes, and the volume of the thoracic cavity decreases, while the pressure within it increases. As a result, the lungs contract and air is forced out.