Abstract:
The respiratory system of birds consists of the non-expandable lungs and a series of air sacs providing a unidirectional system of air flow (Maina, 2002). The avian lung is formed by a series of tubular structures, the parabronchi, through which air flows unidirectionally, and a series of air capillaries where gas exchange with the blood takes place (Dunker, 1971; Duncker, 1972; Duncker, 1974; Scheid, 1979). ...