This is a schematic drawing of a small airway with the main tissue components: epithelium, smooth muscle, and some inflammatory cells. The airway is surrounded by alveoli, which are attached to the basement membrane. Blood vessels are also present in the sub-epithelial layer, but are not shown.
The ability to breathe in
The total diameter of all bronchioles is much greater than the diameter of central airways.
Extra info: The diameter of all bronchioles together would produce a larger lumen than that found in the central airways.
The bronchiolar resistance is greatly increased in obstructive lung disease.
Extra info: In contrast to congestive lung disease where the disease is centered in the aveoli, obstructive disease occurs in the bronchioles.