PNB 2265 Chapter Notes - Chapter 6: Functional Residual Capacity, Caseous Necrosis, Epithelioid Cell
Document Summary
Two functions: air into and out of lungs and surface for exchange of o2 and co2 between body tissues in external environment. Upper respiratory tract: external nose, nasal cavity, pharynx. Lower respiratory tract: larynx, trachea, network on bronchioles. Gas exchanged in terminal portions of tree. Contains alveoli - small sac structure formed by respiratory bronchioles in alveolar ducts. Gas exchange does not occur in conducting zone. Gas exchange occurs at alveoli, located at the end of the respiratory bronchioles. Large blood vessels - simple squamous epithelial but also smooth muscle for constriction and dilation. A pathological condition characterized by destruction of the respiratory bronchioles and alveoli. Harder to inflate and more difficult to exhale. Pathological increase in size of remaining alveoli fewer alveoli no gas exchange. Result of fibrous scar tissue formation; destruction of alveoli. Granulomas abnormal necrosis in center of tubercles. Langham cells - giant multi nuclei cells whose nuclei line the ending of cells.