What is the primary role of the intercostal muscles in respiration?

The intercostal muscles play a crucial role in the process of respiration by elevating and depressing the ribcage. During inhalation, the external intercostal muscles contract, which lifts the ribs upwards and outwards, increasing the volume of the thoracic cavity. This expansion allows air to be drawn into the lungs. Conversely, during exhalation, the internal intercostal muscles contract, pulling the ribs downward and inward, which helps to reduce the volume of the thoracic cavity and push air out of the lungs. This coordinated movement is essential for effective breathing and is a fundamental aspect of the respiratory process. Thus, the primary role of the intercostal muscles is directly linked to their ability to facilitate the dynamics of ribcage movement during the breathing cycles.