NUR1 324 Lecture : respiration.doc
Document Summary
Functions of the conducting airways: defence against bacterial infection and foreign particles: The epithelial cells possess cilia and secrete mucous. Foreign particles stick to the mucous and the cilia constantly sweeps the mucous up into the pharynx. Subdivisions of the conducting airways and terminal respiratory units: the airways consist of a series of tubes that branch and become narrower, shorter and more numerous as they penetrate into the lungs. Conducting and respiratory zones: conducting zone: Airways from the mouth and nose openings, all the way down to the terminal bronchioles. They conduct air from environment to the respiratory zone. Since they do not participate in gas exchange, they are said to form the anatomical dead space: respiratory zone: Characterized by the presence of alveoli in the walls of the airways. Begins where the terminal bronchioles divide into the respiratory bronchioles.