Thorax

Thorax

1. Upper part of the trunk

   • Musculoskeletal cage
     • Contains heart, lungs, esophagus, trachea.
       • Separated from ab. area by the diaphragm
         • Protects abdominal internal organs
           • Thoracic capacity: less in females

2. MUSCULOSKELETAL FRAMEWORK

   • Bones and Joints
     • 12 Thoracic vertebrae
     • 12 Pairs of ribs
       • Separated by intercostal spaces
     • Costal cartilages
     • Sternum
       • Cranial manubrium
       • Intermediate body
       • Caudal xiphoid process
   • Muscles
     • Intrinsec
       • Can elevate or depress the ribs
         • Ex.: intercostal muscles,subcostalis,transversus,serratus posterior.
     • Extrinsec

3. DIAPHRAGM

   • Curved musculotendinous sheet
     • Attached to: circumference of the thoracic outlet
       • Forms: floor of thoracic cavity
         • Separates: abdominal cavity
           • Esophagus: passes through muscular part of the diaphragm
             • Enters the abdomen

4. THORACIC CAVITY

   • Pleural cavities
     • Right and left: separated by the mediastinum
       • Space between layers: maintains negative pressure
         • Left pleural cavity
           • Smaller because of the heart

5. VASCULAR SUPPLY

   • Muscles from thoracic wall
     • receive blood supply
       • from internal thoracic artery

6. AUTONOMIC PLEXUSES

   • Cardiac
   • Pulmonary
   • Esophageal