MPPSC 2016 General Studies Solved Paper-1

(D) Lungs are the primary organs of respiration in mammals. They are actively ventilated by inhalation and exhalation which is aided by rib muscles and the diaphragm.Inhalation occurs when the rib cage expands and the diaphragm is pulled down to create suction pressure. This causes air to rush in through the nostrils and fill the alveoli,where the exchange of gases takes place.