ABSTRACT
This chapter provides an overview of the physiology of the airways excluding that of the nasopharyngeal regions of the airways. Aspects considered relevant to the practical and theoretical application of inhaled substances are emphasized. Many factors beyond the anatomy of the airways are relevant to the therapeutic use of aerosols. The epithelium of the airways is a continuous sheet of cells lining the lumenal surface of the airways. Smooth muscle is separated from the epithelium by the lamina propria, a region of connective tissue containing nerves and blood vessels. Mucus hypersecretion results from an increase in the number and/or size of mucous glands and goblet cells in disease states, such as chronic bronchitis. In the central nervous system regulation of airway function, afferent and efferent nerves serving sensory and effector functions, respectively, innervate the airways. The blood supply to the airways of the respiratory zone involves the pulmonary circulation.
