Lobar bronchus to middle lobe

The lobar bronchus for the middle lobe is the secondary bronchus that provides ventilation to the middle lung lobe, present only in the right lung of certain species.

It branches off the right main bronchus and specifically extends towards the right middle lobe. Its wall contains cartilage, smooth muscle, and a ciliated respiratory mucosa.

• Present in: Dog, cat, ruminants (cattle, sheep), and humans.

• Absent in: Horse (which does not possess a distinct middle lobe).

Its role is to distribute air to the middle lobe and to participate in pulmonary defense.