Scanning electron microscopic observations of the human respiratory tract.
As viewed by scanning electron microscopy, the luminal surface of the human trachea at 12 weeks' gestation shows a predominance of microvillous-covered, nonciliated cells, in contrast to the heavily ciliated tracheobronchial surface seen at 34 weeks' gestation. Hyaline membrane disease produces a confluent lining material in the lung periphery that obscures the bronchiolar and alveolar surface architecture. Large saucer-shaped alveoli, numerous alveolar pores, and an abundance of in situ alveolar macrophages are observed in chronic bronchitis and in emphysematous lungs; The scanning electron microscope offers an additional tool for the study of developmental and pathological processes in the human respiratory tract.
D001980:Bronchi / Q000196:embryology / Q000648:ultrastructure; D001991:Bronchitis / Q000473:pathology; D002923:Cilia; D005865:Gestational Age; D006801:Humans; D006819:Hyaline Membrane Disease / Q000473:pathology; D007231:Infant, Newborn; D008168:Lung / Q000196:embryology / Q000648:ultrastructure; D008264:Macrophages / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D011656:Pulmonary Emphysema / Q000473:pathology; D012137:Respiratory System / Q000648:ultrastructure*; D014132:Trachea / Q000196:embryology / Q000648:ultrastructure