The muscles of the thorax consist of the intercostals and diaphragm. The intercostal muscles are arranged as three layers (external layer, internal layer and an incomplete innermost layer) between the ribs. The diaphragm closes the thoracic outlet and separates the thoracic cavity from the abdominal cavity. The three layers of the intercostal muscles are:
As you can see, the innermost layer is split into three differently named muscle groups. The transversus thoracis, innermost intercostal and subcostal muscles make up the deepest layer of muscles from anterior to posterior, respectively.
|diaphragm as seen
Details of the diaphragm will be considered later when the abdomen is examined. We are presently interested in the thoracic surface or the dome of the diaphragm.
|Bones of the Thorax||Nerves & Vessels of Thoracic Wall|
|This is copyrighted©1999 by Wesley Norman, PhD, DSc|