Sternum

selective focus photography of skeleton
  • Lies in midline of anterior chest wall
  • Flat bone 
  • 3 parts: manubrium sterni, body of sternum and xiphoid process
Manubrium 
  • Upper part 
  • Articulates with body at manubriosternal joint
  • Articulates with clavicles, first costal cartilage and upper part of second costal cartilage
  • Lies opposite third and fourth thoracic vertebrae
Body 
  • Articulates above with manubrium at manubriosternal joint
  • Articulates below with xiphoid process at xiphisternal joint 
  • Each side articulates with second to seventh costal cartilages
Xiphoid process
  • Thin plate of cartilage
  • Ossifies at proximal end during adult life
  • No ribs or costal cartilages attached to it 
Sternal angle
  • Angle of Louis
  • Articulation of manubrium with body of sternum 
  • At level of second costal cartilage and opposite to D4-D5 disc
Xiphisternal joint 
  • Opposite body of D9