Innermost intercostal muscle

The innermost intercostal muscle is a layer of intercostal muscles deep to the plane that contains the intercostal nerves and intercostal vessels and the internal intercostal muscles. Innermost intercostal muscle (shown in red). Animation.A cutout of the thoracic wall showing the three layers of intercostal muscle - from the left wall. The innermost intercostal muscle is a layer of intercostal muscles deep to the plane that contains the intercostal nerves and intercostal vessels and the internal intercostal muscles.