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BONES. 97 ;
is not constant, and sometimes two foramina are found in this location.
Occasionally the foramen caecum, the commencement of the longitudinal
sinus of the brain, opens on this surflice.
The Posterior or Internal Surface (Fig. 45) is concave from side to side
and convex from above downward. Upon this surface is a longitudinal
groove (sometimes a canal) for the transmission of the internal branch
of the nasal nerve, which passes out between the bone and the lateral
cartilage of the nose.
The Superior Border is triangular in form, and serrated for articula-
tion in the nasal notch of the frontal bone.
The Inferior Border is the broadest part of the bone. It is thin and
notched in the centre for the transmission of the anterior branch of the
nasal nerve ; this border extends downward, outward, and backward,
it gives support to the lateral cartilage of
terminating in a sharp point ;
the nose. In the articulated skull the inferior borders of the two nasal
bones form a triangular notch called the nasal angle, serving for partial
attachment of the lateral nasal cartilage.
it is ser-
The Latercd or External Border is the longest of the four ;
rated and bevelled at the expense of the anterior surface, and articulates
with the nasal process of the superior maxilla.
The Median or Internal Border at its upper portion is thick, gradu-
ally becoming thinner and tapering as it descends. When the bone
is articulated with its fellow of the opposite side the border produces
internally a vertical crest which forms part of the se})tum of the nose,
and articulates with the nasal spine of the frontal, the perpendicular
plate of the ethmoid bone, and atfords attachment to the nasal carti-
laginous septum.
Developmext.—The nasal bone is developed in membrane from
one point of ossification, which appears about the eighth week of
embryonal life.
The Malar Bones.
The malar (or cheek) bones are two in number, situated at the lateral
angles of the face, and support the most prominent portion of the
cheeks ; they assist in forming the outer wall, lower border, and floor
of the orbit, the anterior portions of the temporal and zygomatic fossae,
and the zygomatic arch. The bone is quadrangular in shape, and pre-
sents for examination a body with two surfaces, external and internal
four proccs-es, frontal, orbital, maxillary, and zygomatic ; and five bor-
ders, superior, inferior, anterior, posterior, and sphenoidal.
Tlie External or Facial Surface (Fig. 4(3) is convex in form ; the
upper portion is smooth, and supports the sphincter muscle of the eye,
the orbicularis palpebrarum ; the lower portion is roughened, and gives
origin to the major and minor zygomatic muscles. The upper portion
of this surface is pierced by one or two foramina, which pass into the
orbit and transmit the terminal ends of the lachrymal blood-vessels
and nerves. The foramina or canals in the malar bone vary with
different subjects : sometimes they are double, and occasionally they are
wanting.
Vol. I.—
BONES. 97 ;
is not constant, and sometimes two foramina are found in this location.
Occasionally the foramen caecum, the commencement of the longitudinal
sinus of the brain, opens on this surflice.
The Posterior or Internal Surface (Fig. 45) is concave from side to side
and convex from above downward. Upon this surface is a longitudinal
groove (sometimes a canal) for the transmission of the internal branch
of the nasal nerve, which passes out between the bone and the lateral
cartilage of the nose.
The Superior Border is triangular in form, and serrated for articula-
tion in the nasal notch of the frontal bone.
The Inferior Border is the broadest part of the bone. It is thin and
notched in the centre for the transmission of the anterior branch of the
nasal nerve ; this border extends downward, outward, and backward,
it gives support to the lateral cartilage of
terminating in a sharp point ;
the nose. In the articulated skull the inferior borders of the two nasal
bones form a triangular notch called the nasal angle, serving for partial
attachment of the lateral nasal cartilage.
it is ser-
The Latercd or External Border is the longest of the four ;
rated and bevelled at the expense of the anterior surface, and articulates
with the nasal process of the superior maxilla.
The Median or Internal Border at its upper portion is thick, gradu-
ally becoming thinner and tapering as it descends. When the bone
is articulated with its fellow of the opposite side the border produces
internally a vertical crest which forms part of the se})tum of the nose,
and articulates with the nasal spine of the frontal, the perpendicular
plate of the ethmoid bone, and atfords attachment to the nasal carti-
laginous septum.
Developmext.—The nasal bone is developed in membrane from
one point of ossification, which appears about the eighth week of
embryonal life.
The Malar Bones.
The malar (or cheek) bones are two in number, situated at the lateral
angles of the face, and support the most prominent portion of the
cheeks ; they assist in forming the outer wall, lower border, and floor
of the orbit, the anterior portions of the temporal and zygomatic fossae,
and the zygomatic arch. The bone is quadrangular in shape, and pre-
sents for examination a body with two surfaces, external and internal
four proccs-es, frontal, orbital, maxillary, and zygomatic ; and five bor-
ders, superior, inferior, anterior, posterior, and sphenoidal.
Tlie External or Facial Surface (Fig. 4(3) is convex in form ; the
upper portion is smooth, and supports the sphincter muscle of the eye,
the orbicularis palpebrarum ; the lower portion is roughened, and gives
origin to the major and minor zygomatic muscles. The upper portion
of this surface is pierced by one or two foramina, which pass into the
orbit and transmit the terminal ends of the lachrymal blood-vessels
and nerves. The foramina or canals in the malar bone vary with
different subjects : sometimes they are double, and occasionally they are
wanting.
Vol. I.—
