Page 685 - Atlas of Histology with Functional Correlations

Olfactory Epithelium

Located in the roof of the nasal cavity and laterally on each side of the
superior conchae

Specialized pseudostratified epithelium consisting of three cell types without
goblet cells
Contains supportive, basal, and olfactory cells, the sensory bipolar neurons
Olfactory cells are the sensory bipolar neurons that respond to smell

Olfactory cells span the thickness of epithelium and end as olfactory vesicles
Surface of vesicles shows radiating nonmotile olfactory cilia that contain
olfactory receptors for odorants
Olfactory cilia contain odorant-binding receptors that are stimulated by odor

molecules
Unmyelinated axons leave bases of olfactory cells to form nerve bundles
Nerve bundles continue through skull bone to synapse in the olfactory bulbs
of the brain

Below epithelium, serous olfactory glands bathe olfactory cilia and provide
odor solvents
Dissolved odorant molecules bind to odorant-binding proteins in fluid
produced by olfactory glands

Supportive cells provide structural support, whereas basal cells serve as stem
cells for the olfactory epithelium
Transition from olfactory to respiratory epithelium is abrupt

Respiratory System—Conducting Portion

Extrapulmonary structures are the nose, pharynx, larynx, trachea, and
extrapulmonary bronchi

Intrapulmonary structures include bronchi, bronchioles, and terminal
bronchioles
Conditions air by humidifying, warming, and filtering it because of cilia and

mucus
Secretions from glands contain immunoglobulins, lysozyme, and enzymes to
kill bacteria
Incomplete hyaline cartilage C rings encircle and keep trachea patent (open)
In the lungs, hyaline cartilage plates replace C rings and encircle the larger

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