Histology
University of BPUMS
Bushehr University of Medical Sciences
Histology : The Respiratory System
-Nasal cavities
1. Respiratory Epithelium
2. Olfactory Epithelium
3. Paranasal Sinuses
pg. 1
, -Respiratory Epithelium
(ciliated pseudostratified columnar epithelium)
Most of the nasal cavities and conducting portion of the system is lined
with mucosa having ciliated pseudostratified columnar epithelium,
described with epithelia commonly known as respiratory epithelium.
This epithelium has five major cell types, all of which contact an
unusually thick basement membrane:
1. Ciliated columnar cells are the most abundant, each with 250-300 cilia on
its apical surface .
2. Goblet cells are also numerous and predominate in some areas with basal
nuclei and apical domains filled with granules of mucin glycoproteins.
3. Brush cells are a much less numerous, columnar cell type, in which a small
apical surface bears sparse, blunt microvilli . Brush cells are chemosensory
receptors resembling gustatory cells, with similar signal transduction
components and synaptic contact with afferent nerve endings on their basal
surfaces.
4. Small granule cells (or Kulchitsky cells) are difficult to distinguish in
routine preparations but possess numer- ous dense core granules 100-300 nm
in diameter. Like enteroendocrine cells of thegut, they are part of the diffuse
neuroendocrine system (DNES) . Like brush cells, they represent only
about 3% of the cells in respiratory epithelium.
5. Basal cells are mitotically active stem and progenitor cells that give rise to
the other epithelial cell types.
pg. 2
, Respiratory epithelium
pg. 3
University of BPUMS
Bushehr University of Medical Sciences
Histology : The Respiratory System
-Nasal cavities
1. Respiratory Epithelium
2. Olfactory Epithelium
3. Paranasal Sinuses
pg. 1
, -Respiratory Epithelium
(ciliated pseudostratified columnar epithelium)
Most of the nasal cavities and conducting portion of the system is lined
with mucosa having ciliated pseudostratified columnar epithelium,
described with epithelia commonly known as respiratory epithelium.
This epithelium has five major cell types, all of which contact an
unusually thick basement membrane:
1. Ciliated columnar cells are the most abundant, each with 250-300 cilia on
its apical surface .
2. Goblet cells are also numerous and predominate in some areas with basal
nuclei and apical domains filled with granules of mucin glycoproteins.
3. Brush cells are a much less numerous, columnar cell type, in which a small
apical surface bears sparse, blunt microvilli . Brush cells are chemosensory
receptors resembling gustatory cells, with similar signal transduction
components and synaptic contact with afferent nerve endings on their basal
surfaces.
4. Small granule cells (or Kulchitsky cells) are difficult to distinguish in
routine preparations but possess numer- ous dense core granules 100-300 nm
in diameter. Like enteroendocrine cells of thegut, they are part of the diffuse
neuroendocrine system (DNES) . Like brush cells, they represent only
about 3% of the cells in respiratory epithelium.
5. Basal cells are mitotically active stem and progenitor cells that give rise to
the other epithelial cell types.
pg. 2
, Respiratory epithelium
pg. 3
