THE CIRCULATORY OR VASCULAR SYSTEM III 



The pericardiac arteries are small and irregular, and 

 are distributed to the pericardium. 



The bronchial arteries are three in number one 

 for the right lung and two for the left ; they are distributed 

 to the lung-tissue, and also provide small branches that 

 supply the bronchial glands, esophagus, and peri- 

 cardium. 



The esophageal arteries number five or six; they 

 are given off from the anterior part of the aorta, and are 

 distributed to the esophagus, forming a chain of arterial 

 supply about it. They anastomose freely with the ar- 

 teries in the vicinity. 



The posterior mediastinal arteries are small, and 

 are distributed to the lymphatic glands and cellular tissue 

 of the posterior mediastinum. 



The intercostals (posterior) arise from the posterior 

 part of the aorta, and number ten on each side. The 

 first intercostal space is supplied by the superior inter= 

 costal artery, a branch of the subclavian. They 

 anastomose freely with the anterior intercostal, mam- 

 mary, axillary, epigastric, phrenic, and lumbar arteries. 

 They supply the vertebrae, spinal cord, dorsal muscles, 

 and skin. 



THE ABDOMINAL AORTA 



This important structure has been briefly described 

 in another section (page 97). For the purpose of 

 making the nurse more familiar with this artery and 

 its branches, a more complete description will now be 

 given. 



The abdominal aorta commences at the aortic opening 

 in the diaphragm, in front of the body of the last dorsal 

 vertebra ; descending to the left of the vertebral column, it 

 terminates on the body of the fourth lumbar vertebra 

 by dividing into the right and left common iliac 



