330 DISSECTION OF THE BABBIT 



a. The vertebral artery arises from the sub- 

 clavian just beyond its origin, and passing 

 dorsalwards enters the vertebrarterial canal 

 of the cervical vertebrae, along vyhich it 

 passes, supplying the spinal cord and the 

 brain. 



/3. The internal mammary artery arises from the 

 subclavian just before it leaves the thorax, 

 and runs backwards along the inner surface 

 of the ventral wall of the thorax. 



ii. The right carotid artery runs forwards along- 

 side the trachea, supplying the neck. Oppo- 

 site the angle of the jaw it divides into (1) the 

 internal carotid artery, which enters the skull 

 through the carotid foramen to supply the 

 brain ; and (2) the external carotid artery, 

 which supplies the right side of the head and 

 face. 



iii. The left carotid artery corresponds to the 

 right carotid in its course and distribution. 



b. The left subclavian artery arises from the left side 



of the arch of the aorta : its course and branches 

 correspond to those of the right subclavian. 



c. The intercostal arteries are a series of small paired 



arteries, arising from the dorsal surface of the 

 aorta, and running outwards on the inner surface 

 of the thoracic walls, one behind each rib. 



3. Arteries arising from the aorta in the abdomen. 



a. The coeliac artery is a large median vessel, arising 



from the ventral surface of the aorta, about half 

 an inch behind the diaphragm. It runs in the 

 mesentery, and divides into the hepatic artery 

 supplying the liver, and the lieno-gastric artery 

 supplying the stomach and spleen. 



b. The anterior mesenteric artery is a large median 



vessel, arising from the aorta about three-quarters 



