Nasal secretions are composed of two elements, mucus and water. Glycoproteins are produced by the mucus glands and the water and ions are produced mainly from the serous glands and indirectly from transudation from the capillary network. There are also two secretory cell types in the mixed nasal glands, mucus and serous cells.
Glycoproteins found in mucus are produced in two cell types, the goblet cells within the epithelium and the glandular mucus cells. Glandular mucus and goblet cells contain large electron-lucent secretory granules, containing acidic glycoproteins. Serous cells contain discrete electron dense granules. Granules may have a core of greater density. They contain neutral glycoproteins,enzymes such as lysozymes and lactoferrin as well as immunoglobulins of the IgA2 subclass. Submucosal glands are mixed and are arranged around ducts. The anterior part of the nose contains serous glands only in the vestibular region. These produce a copious watery secretion when stimulated. Sinuses have fewer goblet cells and mixed glands.