Structure of the human uvula

Eleven uvular biopsies were investigated for their morphology, the presence of mast cells and the: distribution of hyaluronan and its major ligand CD4 4. Three microanatomical sites - surface epithelium, subepithelial area and area of glands - were examined. The oral side of the uvula was covered by a 15-20 cell thick layer of keratinized/parakeratinized surface epithelium, firmly anchored to the underlying connective tissue by connective tissue p apillaeas. The width of the intercellular spaces in the epithelium increase d toward the basal lamina. a location that exhibited intense hyaluronan and anti-CD44 staining. Most mast cells were located in the vicinity of blood vessels, at which sites there uas high staining intensity of hyaluronan. Ti ssue mast cells could also be observed in the connective tissue septa enclo sing the acini. Glands and muscle fibres became more sparse from the proxim al part of the uvula to the distal end. while the amount of connective tiss ue increased. The localization and architecture of connective tissue elemen ts and mast cells are consistent with the ability of the uvula to resist me chanical stresses and to develop oedema and fibrosis, respectively.