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226 ANATOMY. — ;
The Angular Artery is properly the continuation of the facial. It
ascends between the inner canthus of the eye and the nose, and its
branches supply tlie tissues in this region, including the lachrymal
sac. It anastomoses with the infraorbital and the nasal branch of the
ophthalmic.
Variations.—The facial artery may arise in conjunction with the
lingual and superior thyroid, and it may also have its origin above the
carotid triangle. When this is the case, it descends to its normal posi-
tion below the jaw. It may interchange with the internal maxillary
(deep facial) artery. It varies in size and distribution. Rare instances
are recorded where the artery has not passed upon the face, but has ter-
minated in the submental. At times it extends in the face only far
enough to supply the lower lip, and it frequently fails to give olf the
lateral nasal and angular branches. When the facial artery is abnor-
mallv short, and fails to extend to its usual termination upon the
face, the blood-supply is received through the enlargement of the nasal
branch of the ophthalmic and branches of the transverse facial (a divis-
ion of the temporal artery), or through one or more of the terminal
branches of the internal maxillary. In cases where any of these arteries
are small in size or entirely absent the facial artery may be increased
in size to supply the deficiency. Occasionally, while in the neck the
facial may give off a branch to supply the sublingual gland, the gland
in such case not receiving its usual supply from the lingual.
The Occipital Artery.
The occipital artery is about 3|- mm. (| inch) in calibre, and arises
from the surface of the external carotid, opposite to, or slightly above,
the facial. From this origin, which is beneath the sterno-cleido-mas-
toid and the posterior belly of the digastric muscle, it passes upward
and backward, and is covered by the posterior belly of the digastric and
the stylo-hyoid muscle and a portion of the parotid gland. The hypo-
glossal nerve crosses it on its outer side. It then passes to the outside
of the internal jugular vein, the pneuraogastric and spinal accessory
nerves, to an interspace between the transverse process of the atlas and
the mastoid process of the temporal bone. When it reaches the base of
the skull it is directed backward, following the occipital groove situated
to the inner side of the digastric fossa on the temporal bone. It lies
beneath the muscles attached to the mastoid process, and above the
superior oblique, complexus, and rectus posticus major muscles. When
it reaches the extremity of the groove it turns upward, passing througli
the trapezius muscle, then over the occiput, being distributed to the
structures in this region, and anastomoses with the temporal artery and
corresponding artery of the opposite side.
The branches of the occipital artery are
1. The muscular 4. Posterior meningeal
;
2. The auricular 5. Mastoid
; ;
3. Descending cervical 6. Superficial or cranial.
The Muscular Arteries consist of several small branches which supply
the posterior belly of the digastric, the stylo-hyoid, splenius capitis, and
226 ANATOMY. — ;
The Angular Artery is properly the continuation of the facial. It
ascends between the inner canthus of the eye and the nose, and its
branches supply tlie tissues in this region, including the lachrymal
sac. It anastomoses with the infraorbital and the nasal branch of the
ophthalmic.
Variations.—The facial artery may arise in conjunction with the
lingual and superior thyroid, and it may also have its origin above the
carotid triangle. When this is the case, it descends to its normal posi-
tion below the jaw. It may interchange with the internal maxillary
(deep facial) artery. It varies in size and distribution. Rare instances
are recorded where the artery has not passed upon the face, but has ter-
minated in the submental. At times it extends in the face only far
enough to supply the lower lip, and it frequently fails to give olf the
lateral nasal and angular branches. When the facial artery is abnor-
mallv short, and fails to extend to its usual termination upon the
face, the blood-supply is received through the enlargement of the nasal
branch of the ophthalmic and branches of the transverse facial (a divis-
ion of the temporal artery), or through one or more of the terminal
branches of the internal maxillary. In cases where any of these arteries
are small in size or entirely absent the facial artery may be increased
in size to supply the deficiency. Occasionally, while in the neck the
facial may give off a branch to supply the sublingual gland, the gland
in such case not receiving its usual supply from the lingual.
The Occipital Artery.
The occipital artery is about 3|- mm. (| inch) in calibre, and arises
from the surface of the external carotid, opposite to, or slightly above,
the facial. From this origin, which is beneath the sterno-cleido-mas-
toid and the posterior belly of the digastric muscle, it passes upward
and backward, and is covered by the posterior belly of the digastric and
the stylo-hyoid muscle and a portion of the parotid gland. The hypo-
glossal nerve crosses it on its outer side. It then passes to the outside
of the internal jugular vein, the pneuraogastric and spinal accessory
nerves, to an interspace between the transverse process of the atlas and
the mastoid process of the temporal bone. When it reaches the base of
the skull it is directed backward, following the occipital groove situated
to the inner side of the digastric fossa on the temporal bone. It lies
beneath the muscles attached to the mastoid process, and above the
superior oblique, complexus, and rectus posticus major muscles. When
it reaches the extremity of the groove it turns upward, passing througli
the trapezius muscle, then over the occiput, being distributed to the
structures in this region, and anastomoses with the temporal artery and
corresponding artery of the opposite side.
The branches of the occipital artery are
1. The muscular 4. Posterior meningeal
;
2. The auricular 5. Mastoid
; ;
3. Descending cervical 6. Superficial or cranial.
The Muscular Arteries consist of several small branches which supply
the posterior belly of the digastric, the stylo-hyoid, splenius capitis, and
