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The nose, nasal passages and the paranasal sinuses are important
structures with many functions associated with comfort of breathing,
protection from foreign substance, and sense of smell. The nose
and nasal cavity are divided into two sides by a “wall”
in the center of your nose, called the septum. The septum is composed
of bone and cartilage that is covered by a mucus producing membrane
called the mucosa. Each nostrils open into a nasal passage. Each
of the two nasal passages has a centered wall (the septum) and a
side wall which has boney projections called turbinates. Varying
sized air containing chambers some of which resemble a honeycomb
are situated behind the bones of the face are called the paranasal
sinuses. These sinuses drain into the nasal passages. The roof of
the paranasal sinuses is adjacent to skull base and their side walls
are next to orbits (where the eyes reside). Five pairs of sinuses
and three to four pairs of turbinates are typically present.
The five pairs of sinuses are named the:
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Maxillary sinuses (in our cheeks below our eyes)
- Anterior
ethmoid sinuses ( a honeycomb of small chambers between our eyes
and below the skull base brain)
-
Posterior ethmoid sinuses ( honeycomb of sinuses just behind the
anterior ethmoid sinuses)
- Frontal
sinuses in the forehead region
- Sphenoid
sinuses
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Maxillary
& Ethmoid Sinuses (blue); turbinate
(round pink structures)
(click on image to view enlargement) |
Sense
of smell fibers (stippled white & yellow) reside on the
middle & superior turbinate
(st and mt)
(click on image to view enlargement)
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Frontal
sinus (dark pink top right) , Ant. ethmoid sinuses (green and
yellow), Post.
Ethmoid sinus (blue), sphenoid sinus (pink to left of blue)
(click on image to view enlargement)
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The turbinates are named the:
-
Inferior turbinates – our tear ducts opens underneath this
turbinate.
- Middle
turbinate – the frontal, anterior ethmoid, and maxillary
sinuses drain adjacent to this.
- Superior
turbinate – lies just in front of the sphenoid sinus and
the majority of our sense of smell fibers reside on it and on
the septum across directly across from it.
- Supreme
turbinate – Occasionally these structures are present and
are situated immediately behind the superior turbinates.
The paranasal sinuses connect with the nasal cavity via narrow
openings called ostia that drain through channels adjacent to the
turbinates. Air and mucus enter and exit to and from the sinus through
these openings.
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