Vertebrae (T1-T12)
	Ribs True ribs (1-7) articulate directly with the sternum. False ribs (8-12) do not articulate directly with the sternum. "Floating" ribs are 11-12.
	Sternum manubrium suprasternal notch - level T2 sternal angle of Louis (arrow) - level T4 body - composed of sternebrae xiphoid process (X) -xipersternal joint - level T9-T10.

The thoracic inlet (superior aperture) is bounded by the manubrium, first rib, and T1 vertebra.

The thoracic outlet (inferior aperture) is bounded by the xiphoid process, costal arch, the rib 12. This aperture is closed off by the diaphragm.