The Bronchial Tree and Lobular Division of the Lung of the California Sea Lion (Zalophus californianus).

In the California sea lion (Zalophus californianus), the position of the tracheal bifurcation is fairly cranial compared with those of mammals in general. The right lung has the dorsal, ventral, medial and lateral bronchiole systems. The cranial lobe is formed by the first bronchiole of the dorsal bronchiole system. The middle lobe is formed by the first bronchiole of the lateral bronchiole system. The accessory lobe is formed by the first bronchiole of the ventral bronchiole system. The caudal lobe is formed by the remaining bronchioles of the dorsal and lateral bronchiole systems and all bronchioles of the medial bronchiole system. The left lung has the dorsal and lateral bronchiole systems. The middle lobe is formed by the first bronchiole of the lateral bronchiole system. The caudal lobe is formed by the remaining bronchioles of the lateral bronchiole system and all bronchioles of the dorsal bronchiole system.