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228 ANATOJ\IY. :
The Stijlo-mastokl Artery is long and slender, and enters the stylo-
mastoid foramen in the temporal bone, the facial nerve passing out by
the same (opening. It gives off branches which supply the mastoid cells,
the stapedius muscle, the tympanum, and the semicircular canals of the
internal ear. The continuation antl termination of the stylo-mastoid
it extends forward ^vithin the aquseductus Fal-
artery are very small ;
lopii, anastomosing with the petrosal branch of the middle meningeal,
which is itself a branch of the internal maxillary. In young subjects
the artery that supplies the tympanum comnumicates with the tympanic
branch of the internal maxillary, thus forming a vascular circle around
the tympanic membrane, from which delicate vessels concentrate to
supply that structure.
The Auricular Artery, the other branch of the posterior auricular,
ascends behind the ear and distributes branches to the retrahens aurem
muscle, the posterior portion of the temporal region, and skin over the
mastoid process; two branches to the auricle supply both the inner and
outer surface of the pinna. Besides these, the posterior auricular artery
gives off small muscular twigs which supply the digastric, stylo-hyoid,
sterno-cleido-raastoid, and occipital muscles, the integument, and the
parotid gland.
Variations.—The posterior auricular artery sometimes terminates in
the stylo-mastoid. It is occasionally quite small ; sometimes it is abnor-
mally large, and takes the place of the occi})ital or superficial arteries.
At t'imes it is given off by the occipital artery, and the transverse facial
may arise from the posterior auricular.

The Ascending Pharyngeal Artery.
TJie ascending pharyngeal artery is the smallest of the eight branches
of the external carotid. It is long and slender, and extends in an almost
straight course from its origin to its termination. It usually arises from
the posterior jxirt of the external carotid, from a half to one inch above
the origin of this artery, and passes upward between the external caro-
tid artery and the walls of the pharynx. The branches of the ascend-
ing pharyngeal artery are divided into three sets, as follows
The prevertebral.
The pharyngeal,
The meningeal.
The Prevertebral Arteries are small and are distributed to the longus
colli and rectus capitis anticus muscles, the lymphatic glands of the
neck, sympathetic nerves and ganglia, and some of the nerves passing
out of the base of the brain-case ; finally anastomosing with branches
from the subclavian artery.
7V/C P}iaryv(/eal Arteries, in large measure, suj)ply the nuiscles and
mucous mend)rane of the pharynx. The middle and inferior con-
strictor muscles are usually supj)lie(l by two branches, ^vhich anastomose
with branches of the inferior thyroid artery. A larger and more con-
stant branch is distributed to the su])erior constrictor muscle of the
pharynx, and furnishes small twigs which pass to the Eustachian tube,