Nasal Cavity
Background Information:
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When you enter the lab following lecture, the cadaver’s heads
should be bissected to one side of the nasal septum. Previous examination
of the bony landmarks on a model skull prior to entering the lab will greatly
improve the speed of dissection and understanding of landmarks of the space.
Identification of each of the bones will be assumed.
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A pipecleaner or flexible wire is the best tool for examining
the ducts and pathways by which the sinuses drain into the nasal cavity.
Pipecleaners will be made available to each table in the lab.
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Understand the condition of a deviated nasal septum and its
effect on the patient (breathing and speaking).
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Consider the effects of infection in the sinuses and the
effectiveness of the ducts. Is it surprising that the maxillary sinus
is most prone to infection? What is a suitable treatment for alleviating
an infection in the maxillary sinus?
Dissection:
1. Examine the intact nasal septum and identify
the cartilaginous, bony and membranous portions. Also examine the
bony superior and inferior borders of the nasal cavity, the nasal vestibule,
and the relation of the bulb of the Olfactory Nerve CN1 to the nasal cavity.
2. On the opposite side of the bissected
head, identify the inferior, middle and superior conchae as well as the
corresponding meatus.
3. Examine the exposed sphenoidal and frontal
sinuses.
4. Lift each concha and examine the foramen
by which each sinus drains. With a pipecleaner, verify the drainage
paths of each sinus. For the maxillary and ethmoidal sinuses you
will only be able to identify the openings. Identify the ethmoidal
bulla as well as the semilunar hiatus.
5. Identify the incisive foramen and the
vessels that can pass from the nasal to the oral cavity.
Pictorial Atlas:
Borders of the Nasal Cavity
Concha and Meatuses
Sinuses and Drainage Patterns
Lateral Nasal Wall
Nasal Septum
Nasal Cavity Structures
List