Thorax Surface features Thoracic wall Thoracic cavity
Bony Thorax (Thoracic Cage)
Surface Landmarks
Boundaries of the thorax Superior jugular notch, sternoclavicular joint, superior border of clavicle, acromion, spinous processes of C7 Inferior xiphoid process, costal arch, 12th and 11th ribs, vertebra T12
Thorax Muscles: Intrinsic Intercostales externi Origin: lower border of rib Insertion: upper border of rib below origin Action: elevate ribs adding in forced inspiration Intercostales interni Origin: upper border of rib Insertion: lower border of rib above origin Action: depress ribs for forced expiration
Diaphragm Shape and position: Origin Insertion dome-shaped between thorax and abdomen, consists of a peripheral muscular part and a central tendon Origin Sternal part: xiphoid process Costal part: lower six and costal cartilages Lumbar part: arises from upper 2-3 lumbar vertebrae Insertion central tendon
sternum Ribs
Inspiration movements of: Diaphragm Sternum Ribs
Development of serousal cavities
Pneumo-thorax Lung: collapse
Hemo-thorax
Pneumothorax
Intercostal space