320 THE CIRCULATORY SYSTEM. 
vein comes from the head and face, It is formed by the juric- 
tion of the anterior (Fig. 131, ¢) and posterior (4) facial veins 
near the ventral border of the sternomastoid muscle. It passes 
thence obliquely across the sternomastoid to the triangular 
interval between it and the clavotrapezius. In the interval 
it receives a small branch which accompanies the branch of 
the transversa scapula artery to the clavobrachialis muscle, 
receives next the common trunk of the vena cephalica and 
transversa scapulz, and opposite the cranial end of the 
manubrium receives the internal jugular vein (Fig. 129, Z). 
It then unites with the subclavian to form the innominate 
vein. Near the point where it receives the internal jugular the 
external jugular vein receives the thoracic duct (Fig. 118, 5). 
Branches of the external jugular: 
a. V. transversa scapule.—This follows the course of the 
artery of the same name. One of its branches receives one of 
the two terminal divisions of the vena cephalica (q. v.). In 
many cases veins which correspond to branches of the trans- 
versa scapula artery enter the external jugular separately (as 
shown in Fig. 118, x and 7). 
6. V. cervicalis ascendens.—A small branch which follows 
the corresponding branch of the thyrocervical axis. 
c. V. jugularis interna (Fig. 118, 2; Fig. 119, page 284). 
—The internal jugular vein varies much in size and in the 
place where it joins the external jugular. The point of junction 
is usually at about the level of the first rib, but may be much 
farther craniad. It arises on the ventral side of the basal por- 
tion of the occipital by the junction of a number of veins which 
are described below. The internal jugular passes caudad in 
the neck region at the side of the trachea, in company with the 
common carotid artery and the vagus and sympathetic nerves. 
In this region it receives branches which accompany the 
branches of the common carotid artery. 
The veins which by their union form the internal jugular 
vein are the following: 
(1) One or two veins from the venous sinuses of the brain, 
leaving the cranial cavity by the jugular foramen. These are 
described in the account of the veins of the brain. 
