Chapter 7
The Skeleton
213
7
The Nasal Cavity
Te
nasal cavity
is constructed of bone and hyaline cartilage
(Figure 7.13)
. Te
roof
of the nasal cavity is formed by the
cribriform plates of the ethmoid. Te
lateral walls
are largely
shaped by the superior and middle conchae of the ethmoid
bone, the perpendicular plates of the palatine bones, and the
inferior nasal conchae. Te depressions under cover of the con-
chae on the lateral walls are called
meatuses
(
meatus
5
passage),
so there are superior, middle, and inferior meatuses. Te
floor
of the nasal cavity is formed by the palatine processes of the
The Orbits
Te cone-shaped
orbits
are bony cavities in which the eyes
are firmly encased and cushioned by fatty tissue. Te muscles
that move the eyes and the tear-producing lacrimal glands are
also housed in the orbits. Te walls of each orbit are formed
by parts of seven bones—the frontal, sphenoid, zygomatic,
maxilla, palatine, lacrimal, and ethmoid bones. Teir rela-
tionships are shown in
Figure 7.12
. Also seen in the orbits
are the superior and inferior orbital fissures and the optic ca-
nals, described earlier.
Roof of orbit
Medial wall
Orbital plate
of ethmoid bone
Sphenoid body
Supraorbital notch
Optic canal
Floor of orbit
Orbital process of
palatine bone
Orbital surface of
maxillary bone
Lacrimal bone
Nasal bone
Frontal process
of maxilla
Lateral wall of orbit
Zygomatic process
of frontal bone
Greater wing of
sphenoid bone
Orbital surface of
zygomatic bone
Zygomatic bone
Zygomatic bone
Inferior orbital fissure
Infraorbital groove
Infraorbital
foramen
Superior
orbital fissure
(b) Contribution of each of the seven bones forming the right orbit
(a) Photograph, right orbit
Lesser wing of
sphenoid bone
Orbital plate of
frontal bone
Figure 7.12
Bones that form the orbits.
(For a related image, see
A Brief Atlas of the
Human Body,
Figure 14.)
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