Adilson Monteiro & Ricardo Luiz Smith

Summary

The anatomy of mammal's lung air space constitutes the bronchial tree which disposition is associated to air flux dynamics. Casts obtained from human, pig and rat lungs were studied to analyze possible differences of the bronchial tree architecture in mammals with diverse dimensions and posture. Air spaces were filled with polymers through trachea followed by acid corrosion. Tracheal and main bronchial division's diameters were measured to relate with body mass using allometry. The results revealed a dichotomic bronchial branching pattern in the human casts and a monopodial pattern in animals. In allometric relationship trachea was larger in rats, then pigs and lastly in humans, differences were statistically significant, the same occurs in right bronchus, as in the left bronchus there was no difference between rat and pig. The linear relationship between the human tracheal diameters was 1.2 times larger than the pig and 6.7 times larger than the rat; the pig tracheal diameter was 5.6 times larger than the rat. Quadruped position of the pig and rat is linked to a horizontal air way while the erect position, biped in human, correspond to a vertical air way. A big mammal shows less respiratory frequency than small mammals. Mammals with small, medium and high body mass allied to diverse posture and habits was compared revealing morphological differences in the bronchial trees as different allometric correlations between quadruped animals and human biped.

KEY WORDS: Bronchia; Anatomy; Human; Pig; Rat.

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