During inspiration, which muscle lowers the diaphragm and raises the rib cage?

The external intercostals are the muscles that play a crucial role during inspiration by lowering the diaphragm and raising the rib cage. As these muscles contract, they elevate the ribs and expand the thoracic cavity, which decreases the pressure inside the lungs relative to the atmospheric pressure, allowing air to flow into the lungs. This process is essential for effective breathing, as it facilitates the intake of oxygen.

The function of the external intercostals is particularly important as it helps create the necessary changes in lung volume and pressure during inhalation. Understanding this muscle's role clarifies the mechanics of respiratory function and the body's coordination during breathing. The other muscles mentioned do not primarily contribute to this specific action during inspiration.