As nouns the difference between thorax and mesosternum
is that thorax
is thorax (region of the mammalian body) while mesosternum
is (anatomy) the middle portion, or body, of the sternum.
the middle of three distinct divisions in an insect, crustacean or arachnid body
the region of the mammalian body between the neck and abdomen as well as the cavity containing the heart and lungs
* thoracic vertebra
(anatomy) The middle portion, or body, of the sternum.
(entomology) The ventral piece of the middle segment of the thorax.