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254 ANATOMY.

receives comnmnicatlng branches from the temporal and occipital veins,
and occasionally a branch from the mastoid vein. It passes downward
behind the ear, crosses the mastoid process of the temporal bone and the
npper portion of the sterno-cleido-mastoid muscle, and terminates by
emptying into the external jugular vein.
The Occipital Vein commences on the back of the head, in the
region supplied by the occipital artery. It is formed from a plexus of
small veins and from the communicating branches of its fellow of the
opposite side, as well as from branches which enter the posterior auric-
ular and temporal veins. It generally communicates with the lateral
sinus of the venous system of the brain through the emissary vein, a
branch which traverses the mastoid foramen of the temporal bone. It
extends downward and forward, accompanied by the occipital artery,
and generally terminates by emptying. into the internal jugular, though
occasionally it joins the external jugular.
The Lingual Vein arises from three sources—the ranine, the two
venae comites, and the dorsal veins of the tongue.
The Ha nine or Sublingual Vein is the largest of the branches which
go to form the lingual. It commences by numerous superficial branches
situated on the under surface of the tip of the tongue, and anastomoses
M'ith the corresponding vein of the opposite side. It extends backward,
covered by the mucous membrane of the tongue, and, accompanied by
the hypoglossal nerve, passes to the lateral surface of the hyo-glossus
muscle. Small veins empty into it from the mucous membrane of the
floor of the mouth, the substance of the tongue, and the sublingual
gland.
The Two Vence Comites are two small vessels which accompany the
lingual artery, and terminate by emptying into the lingual vein.
The Dorsal Vein originates in a plexus which is situated on the
under surface of the mucous membrane of the posterior part of the
tongue. These veius occasionally unite to form one common trunk, or
they may break up into several independent branches, which empty
either into the external jugular or the common facial vein. Cases are
reported in which they have emptied into the pharyngeal or internal
jugular vein.
The Pharyngeal Vein originates in the pharyngeal plexus, which
is formed by branches wliich pass from the lateral and posterior walls
of the pharynx. It also receives branches from the soft pakite and
from the Vidian and meningeal veins, w^hich pass through the oval
and spinous foramina in the sphenoid bone, and from the pterygoid
plexus. After receiving these branches it passes downward, and gener-
ally terminates by emptying into the internal jugular vein at the inferior
extremity of the parotid gland, though occasionally it passes into the
common facial vein or unites with the lingual or superior thyroid veins.

VEINS OF THE NECK.

The veins of the neck return the blood from the external and internal
portions of the head and face, the neck, and part of the region of the
shoulder. Thev are as follows :