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234 ANATOMY.
The Pterygoid Branches are not constant in number. They are small and
short ; as their name indicates, they are distributed to the pterygoid muscles.
The JIasseteric Branch is small and regular. It passes outward through
the sigmoid notch of the lower jaw, accompanied by the nerve of the
same name, and is distributed to the masseter muscle. It anastomoses
with the transverse facial artery, and may arise conjointly with the pos-
terior deep temporal. Velpeau is of the opinion that in dislocations of
the jaw this vessel is compressed, and may be ruptured.
the Buccal Brandt is a small vessel which passes downward and for-
ward between the internal pterygoid muscle and the jaw to the outer
side of the buccinator muscle, to which it is distributed. It anasto-
moses with the transverse facial and branches of the facial artery.

ARTEEIES OF THE THIRD DIVISION.
The Alveolar or Superior Ilaxillary Branch generally 'arises with the
infraorbital branch. It passes downward along the zygomatic surface
and tuberosity of the superior maxillary bone, and gives oif small
branches, the posterior dental arteries, which enter the posterior den-
tal canals ; twigs from these supply the superior molar and bicuspid
teeth, and anastomose with the anterior dental portion of the infra-
orbital branch. The mucous membrane of the maxillary sinus is
partly supplied by the posterior dental arteries, offshoots being also
distributed to the alveolar process and gums.
The Infraorbital Branch usually arises conjointly with the alveolar
branch. It passes forward, in companv with the superior maxillary or
infraorbital nerve, along the infraorbital canal, from which it finds exit
upon the face through the infraorbital foramen. In the canal offshoots
are su})plied to the inferi(^r rectus and inferior oblique muscles of the
eye, the lachrymal gland, the connective tissue in the floor of the orbit,
and the mucous membrane of the maxillary sinus. It also gives off the
anterior dental artery, which descends through a canal in the bone to
supply the incisor, cuspid, and bicuspid teeth. This artery anastomoses
with the posterior dental of the alveolar branch, the union, however,
taking place in such a way as to make it difficult to say which artery
supplies the bicuspid teeth. On the face twigs from the infraorbital
supply the lachrymal sac and the surrounding tissue near its exit. They
also anastomose with branchlets of the facial, the nasal of the ophthal-
mic, and the transverse facial and buccal.
The Ih'scendinf/ Palatine or Superior Palatine Branch passes down-
ward in the posterior i)alatine canal, accompanied by the anterior pala-
tine nerves (branches of the s[)lien()-palatine (Meckel's) ganglion), and
emerges upon the posterior and lateral part of the hard palate. It passes
forward in a groove on the hard ])alate to the incisive foramen, at which
point it anastomoses with a branch of the naso-palatine artery. While
in the posterior ]>alatine canal small twigs are given off to the mucous
membrane of the nose and tonsils. It also supplies the hard palate,
alveolar process, ])alatine nuicous glands, nuicous membrane, and the
gum tissue of the suj)erior maxilla, and anastomoses Nvith the ascending
palatine branch of the facial.