98 ANTHROPOLOGY. 
The basal sinuses are, the circular, the cavernous, the superior petrosal, the 
mferiy petrosal, and the occipital. 
Ture IvrernaL JUGULAR VEINS. . The blood from the brain. and cranial 
cavity is received by the internal jugular veins, which are continuous at 
their upper extremities with the lateral sinuses 4 terminate inferiorly i in 
the venz innominate. The junction of the internal jugular vein with the 
lateral sinus takes place in the broad part of the foramen lacerum.. Passing 
down to a level with the os hyoides, it receives the common trunk of the 
facial and temporal veins, and then enlarges considerably. . Previously to 
the junction with the facial vein, it receives the lingual vein from the 
tongue, the pharyngeal from the back and sides of the pharynx, the superior 
thyroid and the occipital from the back of the head. 
THE VERTEBRAL VEINS commence among the deep muscles beneath ie 
occiput, inosculate with the occipital vein, and enter the canal in the trans- 
verse processes between the foramen magnum and the atlas. Descending 
they receive various muscular branches, = empty into the subglanians vein 
nearly opposite to and behind the oe jugular. 
INFERIOR THYROID OR TRACHEAL VEINS form a plexus in oe of Hae 
trachea. . They commence about the thyroid body, and open into the vena 
innominata or into the cava. 
THE Ven# INNomINAT#. These, as already remarked, -unite to. oa 
the superior vena cava. The le/t vena. innominata is about three inches 
long, and receiving the thoracic duct at its commencement, is joined in its 
course by the left vertebral, the inferior thyroid, internal mammary, supe- 
rior phrenic, and mediastinal veins. The right vena is an inch in length, 
and descends almost perpendicularly. It receives at its commencement 
the right absorbent trunk, and in its course the right vertebral vein, and 
sometimes the right Es thyroid and right mammary and Taceaenned 
veins. ! 
THE SUPERIOR VENA Cava descends from the confluence of the venze 
innominate: almost vertically, enters the pericardium, and opens into the 
right auricle behind its appendix. The vena azygos joins it just before it 
enters the pericardium. It returns the blood from the supra-diaphragmatic 
part of the body, and communicates with the inferior vena cava through 
the vena azygos and the vertebral veins. 
THE Azyeos VEINS constitute important appendages to the vens cavee, 
maintaining numerous communications between their branches, securing 
the course of the circulation, notwithstanding any local impediment in any 
particular vessel. The right or greater azygos commences in the abdomen, 
and ascending through the aortic passage of the diaphragm, empties into 
the back part of the superior cava.. It receives several branches, and 
drains the thorax. 
Pl. 183, jig. 1, superficial veins of the head and neck: ’*, pericardium 
displayed; *, right auricle; °*, superior vena cava invested by the. pericar- 
dium; ‘, do. above the pericardium; *, right subclavian; .‘°, root: of the 
internal mammary vein; ’, left subsclavian vein; ° nee jugular; ’, thy- 
roid; *, transverse cervical and scapular Lene , anterior facial vein; 
804 
