After studying this chapter, you should be
● T e structures which are responsible for the inhalation of air, exchange of gases between the air and blood and exhalation of carbon dioxide constitute the respiratory system.
● Apart from respiration, this system is also responsible for olfaction and sound production.
● The respiratory system consists of two parts—a conducting part (which carries air) and a respiratory part (where gas exchange takes place).
In general, the respiratory tract is made of four coats (Fig. ), namely:
It includes the epithelial lining and the underlying lamina propria. The epithelium is usually pseudostratified ciliated columnar epithelium with goblet cells.
It is a layer of loose connective tissue containing mixed glands.
This layer is mostly formed by hyaline cartilage plus smooth muscle.
It is a layer of fibroelastic connective tissue merging with the surrounding tissue.