290 “THE CIRCULATORY SYSTEM. 
foramen in the orbital plate of the frontal bone, then continues 
distad to emerge from the orbit on the medial side of the eye; 
here it anastomoses with branches of the superficial temporal. 
6. A. palatina minor (Fig. 120, #).—The lesser palatine 
artery leaves the internal maxillary distad of the carotid plexus, 
near the caudal border of the maxillary bone. It passes 
ventrocaudad into the soft palate. 
7. A. sphenopalatina.—The sphenopalatine is one of the 
terminal branches of the internal maxillary; it passes mediad 
through the sphenopalatine foramen into the nasal cavity, and 
divides into numerous branches which supply the mucous 
membrane of the nose. It gives off just before it enters the 
sphenopalatine foramen the descending palatine (A. palatina 
descendens), which passes into the posterior palatine canal and 
emerges on the surface of the hard palate, where it ramifies. 
8. A. infraorbitalis (Fig. 120, 0).—The infraorbital artery 
is a direct continuation craniad of the internal maxillary. It 
sends off numerous small branches to the teeth of the upper 
jaw, and a rather large branch which passes to the lower eye- 
lid. It then enters the infraorbital foramen, at the same time 
dividing usually into two or three branches; these emerge from 
the foramen and supply the parts of the nose and upper lip 
adjacent to the foramen (Fig. 131, 7). 
A. SUBCLAVIA. THE SUBCLAVIAN ARTERY. 
The left subclavian (Fig. 118, c) arises from the convexity 
of the aortic arch just distad of the origin of the innominate 
artery, and about two or three centimeters from the heart. It 
passes craniad and slightly to the left, and turns into the left 
arm just craniad of the first rib. : 
The right subclavian (Fig. 115, ) is a direct continuation 
of the innominate, the artery receiving the name subclavian 
after the right common carotid is given off, usually at about the 
level of the second or third intercostal space. 
The subclavian has the following branches: the vertebral 
artery (Fig. 118, g’), the internal mammary (Fig. 118, /), 
the costocervical axis (Fig. 118, g), the thyrocervical axis 
(Fig. 118, 7). Beyond the last-named branch it continues into 
the arm as the axillary artery (Fig. 118, 2; Fig. 122, g). 
