B) Paranasal Sinuses

The paranasal sinuses consist of the frontal, maxillary, ethmoidal and sphenoidal sinuses, all housed within the bone of the same name. They all share common features:

  • They open via a short duct into the lateral wall of the nasal cavity. The locations of these openings vary greatly between individuals
  • They are covered by respiratory epithelium that is thinner than found elsewhere in the respiratory system. There are fewer goblet cells and ciliated cells are found close to the duct openings
  • They are less vascular than the nasal cavity
  • They are rudimentary at birth but enlarge with the eruption of the permanent teeth
  • Their function is unclear

Each set of sinuses will be considered on separate pages.