THE VENA CAVA. 62f 



This portion is styled the abdominal aorta. The first 

 branches given off by the aorta, are those supplying the 

 heart, and consist of the right and left coronary. The next 

 branches in order are those coming off from the arch, and 

 are the arteria innominata, the left carotid, and the left sub- 

 clavian, which supply the neck, head, upper extremities, 

 and part of the wails of the chest. 



The branches of the thoracic aorta (Figs. 8 and 214) 

 come next, and consist of the bronchial arteries, which go 

 to the lungs ; the cesophageal, five or six in number, to the 

 oesophagus ; the posterior mediastinal to the mediastinum ; 

 and the intercostal to the intercostal spaces and walls of 

 the chest. The superior intercostal comes from the sub- 

 clavian. All these arteries are in pairs. 



The abdominal aorta, (Figs. 8 and 214,) the last portion 

 of this tube, gives off the phrenic to the diaphragm. The 

 cceliac, a single trunk, divides into three branches the 

 gastric, hepatic, and splenic, which go to the stomach, liver, 

 and spleen. 



The superior mesenteric artery, about an inch below the 

 coeliac, supplies the small intestines, the right ascending, 

 and transverse portion of the large intestine. 



The emulgent or renal arteries, two in number, come off 

 at right angles, and go to the kidneys. 



The spermatic, long and small, descend to the testicles. 

 These are sometimes branches of the renal. 



The inferior mesenteric, a single trunk, supplies the left 

 colon and rectum. 



The lumbar arteries are in pairs, from three to five in 

 number, and supply the abdominal walls. 



THE SUPERIOR AND INFERIOR VENA CAVA, (Fig. 9.) 



These two great veins, called also the ascending and de- 

 scending cava, with the coronary, return all the blood of 

 the body, and constitute the venous portion of the systemic 

 or general circulation. 



The descending or superior cava returns to the right 

 auricle of the heart all the blood of the body from above 

 the diaphragm. 



