title: [The efferent lacrimal ducts of the human. Morphological and biochemical studies].
abstract: OBJECTIVE
  Infections occur frequently in the region of the efferent tear ducts. Exact knowledge of the anatomical structure and of cellular defense mechanisms is necessary to understand the pathological processes. This study analyzed the efferent tear ducts with regard to physiological function and possible defense mechanism against infections.
  
  
  METHODS
  We used histological, immunohistochemical and electronmicroscopic techniques to investigate the lacrimal systems from 31 body donors aged 54-88 years.
  
  
  RESULTS
  The efferent tear ducts are lined by a double-layered epithelium resting on a broad basement membrane. These cells contain many lipid droplets and secretory vacuoles in their apical part. Inside the epithelium cells are arranged partly in cell groups forming mucous glands, which morphologically resemble goblet cells of the tarsus palpebrae. The secretory products of these cells contain various carbohydrates including sialic acid. Lymphocytes and macrophages are found in the submucosa partly penetrating the epithelium.
  
  
  CONCLUSIONS
  Lipids and mucins of epithelial and goblet cells form a specialized protective layer on the epithelium of the tear ducts which enables easy drainage of tear fluid into the inferior meatus of the nose. Together with immunocompetent cells the protective layer prevents invasion of pathogenetic agents.
authors.affiliation: Klinik für Ophthalmologie an der Christian-Albrechts-Universität Kiel. athale@ophthalmol.uni-kiel.de
authors.forename: A
authors.initials: A
authors.lastname: Thale
authors.forename: F
authors.initials: F
authors.lastname: Paulsen
authors.forename: G
authors.initials: G
authors.lastname: Kohla
authors.forename: R
authors.initials: R
authors.lastname: Schauer
authors.forename: R
authors.initials: R
authors.lastname: Rochels
authors.forename: B
authors.initials: B
authors.lastname: Tillmann
mesh_terms: D000368:Aged; D004848:Epithelium / Q000033:anatomy & histology; D005260:Female; D020397:Goblet Cells / Q000648:ultrastructure; D006801:Humans; D007765:Lacrimal Apparatus / Q000033:anatomy & histology*; D008055:Lipids / Q000032:analysis; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009077:Mucins / Q000032:analysis; D011975:Receptors, Mitogen / Q000032:analysis; D012016:Reference Values
chemical_list: D008055:Lipids; D009077:Mucins; D011975:Receptors, Mitogen
vernacular_title: Die ableitenden Tränenwege des Menschen. Morphologische und biochemische Untersuchungen.