[Ultrastructural aspect of the different levels of the lacrimal system (author's transl)].

Using the transmission electron microscope and the scanning electron microscope, we have found a different ultrastructure at the different levels of the lacrimal system: 1) tarsal conjonctiva: numerous microvilli on a relief of small valleys; 2) lacrimal punctum: the surface of the cell is flat with sparse microvillosti, sparse cilia and strong intercellular junction; 3) external part of the canaliculus: pavement epithelium with numerous microvillositi and pinocytosis, absence of cilia; 4) internal part of the canaliculus: the microvillositi are very small or absent; 5) lacrimal sac: the cilia are arranged by tufts scattered on this malpighian epithelium; 6) nasolacrimal duct: the cilia are numerous; 7) in the nose the cilia are extremely numerous.