Anatomical significance of the sternal angle
- At this height is the intervertebral disk between the fourth and fifth thoracic vertebrae.
- At this height, the trachea branches off into right and left bronchi.
- At this height the aortic arch begins (the transition zone between the ascending aorta -> aortic arch)
- At this height the aortic arch ends (aortic arch -> thoracic aorta transition)
- The second costal cartilage is attached to both sides of this position on the sternum.
- The sternal angles are easily palpable in vivo and can be used as a guide to count the ribs (intercostal space). The Y coordinates of the trunk are provided.