There are twelve pairs of =levatores costarum=.
The =external intercostals= do not occupy the spaces between the costal
cartilages.
The =diaphragm= has a small tendinous center. The =œsophageal opening=
is between the pillars. The fleshy rim is attached at the costo-chondral
junctions from the eighth backward, and along the thirteenth rib nearly
its entire length.