Air enter nostrils, trachea, syrinx, 2 primary bronchi, 75% into posterior air sacs and 25% into lungs, air form lungs into 7 other air sacs. Have 9 air sacs in total. Also used for heat control and shock absorbers. 2 cycles in breathing, 1st inspiration, through trachea into posterior air sacs 1st exhalation pushes air into parabronchi, 2nd inspiration air is pushed into anterior air sacs 2nd expiration air leaves.