What are the key muscles involved in the process of breathing?

The Role of Key Muscles in Breathing Process

Diaphragm: The diaphragm is a dome-shaped muscle located at the base of the lungs. When it contracts during quiet inspiration, it flattens out, expanding the thoracic cavity and creating a vacuum effect that allows air to rush into the lungs. During quiet expiration, the diaphragm relaxes, returning to its dome shape, which causes air to be expelled from the lungs passively.

External Intercostal Muscles: The external intercostal muscles are located between the ribs. When they contract during quiet inspiration, they lift the rib cage, further expanding the thoracic cavity and aiding in inhalation. These muscles play a crucial role in increasing lung volume. In contrast, during quiet expiration, the external intercostal muscles relax, allowing the rib cage to return to its normal position.

In summary, during quiet breathing, the diaphragm and external intercostal muscles work together to facilitate the process of inhalation and exhalation, ensuring the smooth flow of air in and out of the lungs.