The three layers are: external intercostal muscles, internal intercostal muscles, and the innermost intercostal muscles. These muscles are innervated and supplied with blood by the intercostal nerves, intercostal veins, and intercostal arteries.hey raise the ribs and expand the chest cavity, and originate from ribs one through 11, with insertion from ribs two to 12. The internal intercostal muscles are responsible for forced exhalation. They depress the ribs and decrease space in the chest cavity.
synergism (sinÂ´urjizÉm), n a joint action of two drugs in such a manner that one supplements or enhances the action of the other to produce an effect greater than that which may be obtained with either one of the drugs in equivalent quantity or produce effects that could not be obtained with any safe quantity of either drug, or both.
syllogism in philosophy is counterpart of hypothetical syllogism in mathematics. syllogism in philosophy belongs to logic branch and in mathematics it also belongs to propositional logic. They're really close.