Bronchi (one Bronchus) are the large air tubes leading from the trachea to the lungs. The bronchi have cartilage as part of their supporting wall structure. The trachea divides to form the right and left main bronchi. These divide to form the lobar, segmental, and finally the subsegmental bronchi. It should also be noted that the right bronchus (depicted on the left in the adjacent image) is shorter, wider and more vertical than its counterpart.
Its function is to carry air through the lung tissue.