Which muscles between the ribs expand and contract the rib cage in breathing process?

Which muscles between the ribs expand and contract the rib cage in breathing process?

• A. Intercostal Muscles
• B. Diaphragm
• C. Abdominals
• D. Trachea

Answer: (A)

Intercostal muscles, the muscles between the ribs, are responsible for expanding and contracting the rib cage during breathing. When you inhale, the external intercostals lift the ribs and widen the chest, increasing the thoracic volume so air can enter the lungs. For expiration, especially if it's forced, the internal intercostals pull the ribs downward and inward to reduce chest volume. The diaphragm also aids breathing by contracting to flatten and drop the floor of the thoracic cavity, but it isn’t located between the ribs. Abdominal muscles can assist in forceful expiration by increasing abdominal pressure, while the trachea is an airway, not a muscle.

Intercostal muscles, the muscles between the ribs, are responsible for expanding and contracting the rib cage during breathing. When you inhale, the external intercostals lift the ribs and widen the chest, increasing the thoracic volume so air can enter the lungs. For expiration, especially if it's forced, the internal intercostals pull the ribs downward and inward to reduce chest volume. The diaphragm also aids breathing by contracting to flatten and drop the floor of the thoracic cavity, but it isn’t located between the ribs. Abdominal muscles can assist in forceful expiration by increasing abdominal pressure, while the trachea is an airway, not a muscle.