Page 245 - My FlipBook

BLOOD-VESSEL SYSTEM OF THE HEAD, ETC. 255 ;

External jugular, Internal jugular,
Anterior jugular, Vertebral.
The External Jugular Vein returns the principal portion of the
blood from the internal surface of the face and the external surface of
the head. It commences within the parotid gland near the angle of the
inferior maxillary bone. It is formed by the confluence of the posterior
auricular and the posterior division of the temporo-maxillary veins
it passes almost perpendicularly downward. Its position is indicated
by a line drawn from the angle of the inferior maxilla to the middle
of the clavicle. It is quite superficially situated, being covered only by
the skin and the platysma myoides muscle. It is crossed about its centre
by the superficial cervical nerve. After leaving the angle of the jaw it
passes over the sterno-cleido-mastoid muscle, along its posterior margin,
to a point just above the clavicle, where it pierces the deep fascia of the
neck. It then extends slightly inward, and generally terminates by
emptying into the subclavian vein in close relation to the external bor-
der of the anterior scalenus muscle. Occasionally it terminates by
emptying into the internal jugular vein or at the point of junction of
the internal jugular and subclavian veins. The external jugular is
furnished with two sets of valves, one of which is imperfect and situ-
ated at its termination ; the other set is perfect and located about an
inch and a half above the clavicle.
Tributaries.—The tributaries of the external jugular vein are the
posterior external jugular, transverse cervical, and suprascapular.
The Posterior External Jugular Vein commences by numerous
branches, which are situated in the muscles, skin, and fascia in the
region of the occiput and posterior portion of the neck. It terminates
by emptying into the external jugular vein midway between the clavicle
and the angle of the jaw.
The Transverse Cervical and Suprascapular ^^eins return the blood
from the region of the shoulder, and closely follow the course of the
suprascapular and transversalis colli arteries. These veins are sup-
plied with valves.
The Anterior Jugular Vein varies considerably in size, and is
not constant in its existence. It commences below the chin, nearly in
the median line, by branches situated in the suprahyoid region, the
lower lip, and the chin. It also receives a communicating branch
from the submental vein. It passes downward, in close relation to the
middle of the neck, in a line with the sternal extremity of the clavicle.
Slightly above the clavicle it pierces the deep fascia of the neck, passes
outward and downward, behind the sterno-cleido-mastoid muscle, and
generally terminates by emptying into the lower extremity of the exter-
nal jugular vein, though occasionally it empties into the subclavian vein.
Just after this vein pierces the deep fascia it generally receives a com-
municating branch from the facial vein, and also small branches from
the larynx, and occasionally from the thyroid body. The transverse
cervical and suprascapular veins sometimes terminate in the anterior
jugular vein. The anterior jugular veins of both sides occasionally com-
municate through small branches which extend from the lower extrem-
ities, one branch usually being of considerable size, and passing through