MUSCLES OF RESPIRATION. When the diaphragm contracts in inspiration, initially the lower ribs are fixed and the dome of the diaphragm descends, thus increasing the vertical diameter of thorax.
arrearage. 1  the state or condition of being in arrears. 2  Often, arrearages. arrears; amount or amounts overdue. 3  Archaic. a thing or part kept in reserve.
noun. 1  Arrears is defined as a situation when a person is behind on a deadline or has an unfinished obligation or business. 2  The definition of arrears is a past due debt or an unfulfilled obligation.