The secondary bronchi supply air to each of the five lobes in the lungs. There are five secondary bronchi — three serve the lobes of the right lung, and two serve the lobes in the left lung.
The trachea, or windpipe, splits into two main forks known as the right bronchi and left bronchi. The bronchi then split further into the secondary bronchi, which feed air to each of the five lobes of the lungs. Both lungs contain superior and inferior lobe bronchi, while the right lung also contains a middle lobe bronchi. The bronchi continue to subdivide into tertiary bronchi and eventually into bronchioles.