gms | German Medical Science

76. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

04.05. - 08.05.2005, Erfurt

Efferent tear duct of human and dog - signification of MUC5AC for tear flow

Meeting Abstract

  • corresponding author Roman Hirt - HNO, MLU Halle, Halle
  • Stephen Carrington - Veterinary Anatomy, UCD Dublin, Dublin, Ireland
  • Richard Arnett - Veterinary Anatomy, UCD Dublin, Dublin, Ireland
  • Eamonn FitzPatrick - Veterinary Aanatomy, UCD Dublin, Dublin, Ireland
  • Bernard Tillmann - Anatomisches Institut, CAU Kiel, Kiel
  • Friedrich Paulsen - Anatomisches Institut, MLU Halle, Halle

Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie. 76. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e.V.. Erfurt, 04.-08.05.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05hno420

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/hno2005/05hno200.shtml

Veröffentlicht: 22. September 2005

© 2005 Hirt et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

The purpose of the study was to compare the nasolacrimal system of long nosed dogs to see how closely it resembles the human and to draw conclusions on the mechanism of tear flow.

The nasolacrimal systems of ten long nosed dogs and ten human were investigated by gross anatomy, light microscopy, immunohistochemistry and scanning electron microscopy.

The canine efferent tear duct system consited of the upper and lower canaliculi and the nasolacrimal duct measured about 10 cm. The latter ran from the lacrimal fossa medioanteriorally and opened at the front right beneath the anterior turbinate ( maxillo-turbinate ) in the nose, with an extra opening right above the upper canine tooth. The canaliculi and the final fourth of the duct were lined by squamous epithelium whereas the other parts of the duct revealed a double layered epithelium with a superficial columnar layer and an underlying basal cell layer. No goblet cells were integrated into the epithelium against the human situation. Subepithelially, the lamina propria was composed of two strata: (1) loose connective tissue containing elastic fibers and lymphatic cells and (2) a rich venous plexus comparable to a cavernous body. At the beginning of the final third of the duct several serous glands were situated in the lamina propria opening into the lacrimal passage with their excretory ducts. Moreover mucosa associated lymphoid tissue was visible consiting of lymphoid follicles placed near the opening of the duct right above the upper canine tooth. The immunohistochemistry revealed immature (weak glycolisation) MUC5AC produced in the epithelium of the canine tear duct, mature (strong glycolisation) MUC5AC was only deteceted in human efferent tear duct.

The canine efferent tear duct passage differs in its length, the presence of squamous epithelium at the end of the nasolacrimal duct and the absence of goblet cells from human. The absence of mature MUC5AC in the canine efferent tear duct system could have a function in easing tear flow through the nasolacrimal passage within the meaning of a reduced viscosity.