An amphibian ventilates its lungs by __, inflating the lungs with forced airflow. During the first stage of inhalation, muscles lower the floor of an amphibian's oral cavity, drawing in air through its nostrils. Next, with the nostrils and mouth closed, the floor of the oral cavity risess, forcing air down the trachea. During exhalation, air is forced back out by the elastic recoil of the lungs and by compression of teh muscular body wall. When male frogs puff themselves up in aggressive or courtship displays, they disrupt this breathing cycle, taking in air several times without allowing any release.
+ pressure breathing