Trachea and Bronchi have a similar structure, the bronchi is narrower than the trachea. They both have thick walls that have several layers of tissue:
- much of the wall = cartilage
- cartilage = c shape in trachea (less regular in bronchi)
- inside cartilage = layer of glandular and connective tissue, elastic fibres, smooth muscle and blood vessels - 'loose tissue'
- inner lining = epithelium layer with 2 types of cells: ciliated epithelium and goblet cells
The bronchioles: much narrower, larger ones have some cartlige, wall = smooth muscle and elastic fibres, have alveoli at their ends