Essentials of Anatomy and Physiology

116 The Skeletal System

Palatine process (maxilla)

Palatine bone

Zygomatic bone

Vomer

Zygomatic process

Temporal bone

Styloid process

External auditory meatus

Mastoid process

Occipital condyles

Foramen magnum

Occipital bone

Figure 6–7. Skull. Inferior view with mandible removed.

QUESTION:What is the purpose of the foramen magnum?

Of the 14 facial bones, only the mandible(lower
jaw) is movable; it forms a condyloid jointwith each
temporal bone. The other joints between facial bones
are all sutures. The maxillaeare the two upper jaw
bones, which also form the anterior portion of the
hard palate (roof of the mouth). Sockets for the roots
of the teeth are found in the maxillae and the
mandible. The two nasal bonesform the bridge of
the nose where they articulate with the frontal bone
(the rest of the nose is supported by cartilage). There
is a lacrimal boneat the medial side of each orbit; the
lacrimal canal contains the lacrimal sac, a passageway
for tears. Each of the two zygomatic bonesforms the
point of a cheek, and articulates with the maxilla,
frontal bone, and temporal bone. The two palatine
bonesare the posterior portion of the hard palate.

The plow-shaped vomerforms the lower part of the

nasal septum; it articulates with the ethmoid bone. On

either side of the vomer are the conchae, six scroll-

like bones that curl downward from the sides of the

nasal cavities; they help increase the surface area of the

nasal mucosa. These facial bones are included in Table

6–2.

Paranasal sinusesare air cavities located in the

maxillae and frontal, sphenoid, and ethmoid bones

(Fig. 6–9). As the name paranasalsuggests, they open

into the nasal cavities and are lined with ciliated

epitheliumcontinuous with the mucosa of the nasal

cavities. We are aware of our sinuses only when they

become “stuffed up,” which means that the mucus

they produce cannot drain into the nasal cavities. This

may happen during upper respiratory infections such

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