650 BLOOD-VASCULAR SYSTEM OF THE HORSE 



the nerve of the same name, and is continued forward within the jaw to the incisor 

 teeth. It gives branches to the teeth and gums, and detaches a branch through the 

 infraorbital foramen which anastomoses with the lateral nasal and superior labial.^ 

 About midway between its origin and the maxillary foramen it gives off the malar 

 branch (Ramus malaris), which passes along the floor of the orbit to end in the lower 

 lid and anastomose with the angularis oculi. It gives twigs to the inferior oblique 

 muscle and the lacrimal sac. 



(3) The lesser palatine artery (A. palatina minor) is a small vessel which 

 passes forward in the groove at the medial side of the maxillary tuberosity to the 

 soft palate. In the groove it is accompanied by the nerve of the same name and the 

 palatine vein. 



(4) The sphenopalatine artery (A. sphenopalatina) arises in the anterior 

 part of the pterygo-palatine fossa, passes through the sphenopalatine foramen into 

 the nasal cavity, and divides into two branches. The medial branch is distributed 

 to the mucous membrane of the septum nasi; the lateral one goes to the ventral 

 turbinate, the ventral meatus, the posterior nares, and the maxillary and frontal 

 sinuses. It may arise from the infraorbital. 



(5) The greater palatine artery (A. palatina major) is the direct continuation 

 of the internal maxillary. It passes through the palatine canal to the roof of the 

 mouth, accompanied by the palatine nerve, and runs forward in the palatine 

 groove, where it is joined by the vein. A little behind the plane of the corner 

 incisor teeth it curves medially over a bar of cartilage to the foramen incisivum, 

 where it unites with its fellow of the opposite side. The single artery thus formed 

 (A. palato-labialis) passes up through the foramen and divides under the transversus 

 nasi into two branches. These ramifj^ in the upper lip and anastomose with the 

 lateral nasal and superior labial arteries. In its course in the palate the artery gives 

 off branches to the hard and soft palate and the gums, and others which pass through 

 the accessory palatine foramina to be distributed in the mucous membrane of the 

 lower part of the nasal cavity. Commonly two branches, right and left, are de- 

 tached from the convexity of the arch formed by the union of the two arteries; 

 these run forward in the anterior part of the hard palate. 



Arteries of the Thoracic Limb 

 the brachial artery 



The brachial artery, after crossing the ventral border of the scalenus at the 

 first rib, passes backward and downward across the origin of the coraco-brachialis 

 and the insertion of the subscapularis muscle at the medial side of the shoulder 

 joint. ^ At the posterior border of the subscapularis it gives off the subscapular 

 artery, and turns distally on the medial surface of the arm. In its course in the 

 arm it inclines a little forward, crosses the humerus very obliquely, and is continued 

 by the median artery. 



In its course over the chest-wall the artery is related medially to the ventral 

 border of the serratus thoracis and the rectus thoracis. Opposite the ventral end 

 of the first rib it is crossed medially by the median nerve and laterally by the mus- 

 culo-cutaneous nerve; the two nerves unite below the arterj^, which is thus sus- 

 pended in a sort of loop. In the arm it is related medially to the posterior deep 

 pectoral muscle and is covered by the deep brachial fascia. Laterally it lies on the 

 subscapularis, the brachialis, the insertion of the teres major and latissimus dorsi, 



^ The infraorbital artery is usually small at its emergence upon the face, but in some cases it 

 is rather large and may partially replace the superior labial and lateral nasal arteries. 



^ The term axOlary is often applied to the artery from the first rib to the point of origin of 

 the subscapular artery, and the name brachial is given to the artery beyond this. 



