Gross Morphological Studies on the Trachea of Adult Emu

Abstract

This study was conducted to elucidate the gross morphology of the trachea of emu. The trachea was a cartilaginous, compressible tube of considerable length with tracheal pouch and was elastic in nature. The trachea was formed by the total of 89.5±1.23 tracheal rings, 56.5±0.82 rings were above the tracheal opening, 6.5±0.95 rings correspond to the tracheal pouch (open portion) of the tube and 26.4±0.72 rings were noticed below the open portion to the bifurcation of right and left bronchi. Proximal to the pouch, the rings were complete and broad whereas, distal to the pouch they were complete and narrow. At the bifurcation of left and right bronchi, the rings were incomplete and they were membranous at their continuation into the lungs. The diameter of the tracheal rings gradually increased and at the pouch it was very large and started to decrease distally. The peculiar organization of tracheal pouch in emu was connected with the different vocal powers of this bird.