Lobar bronchus to accessory lobe

The lobar bronchus for the accessory lobe is a bronchial division essential for ventilating the accessory lobe, a specific part of the right lung in many domestic mammals.

This second-generation bronchus emerges from the ventro-medial surface of the right main bronchus, after the bronchus to the middle lobe. It heads toward the accessory lobe, which is located caudal to the heart, ventral to the caudal vena cava, and cranial to the diaphragm.

• Dog and Cat: Present and consistent, ventilating the accessory lobe of the right lung.

• Ruminants: Also present, supplying a well-defined accessory lobe.

• Horse: Absent, as the horse does not possess a distinct accessory lobe.

In humans, there is no distinct accessory lobe. The lobar bronchus for the accessory lobe in animals is homologous to the medial basal segmental bronchus (B7) of the human right lower lobe.