284 PHRENIC ARTERIES. 



Representation of the Diaphragm, the Situation of the Heart, 

 the Blood-vessels of the Breast, and Abdominal Aorta. (See 

 Plate VII. facing page 284.) 



A. The Diaphragm, dividing the thorax from the abdomen. 



B. The Heart, lying upon the diaphragm^ and with the apex obliquely to 



the left side, 

 c. The Right Auricle. 



D. The Left Auricle; that which receives the blood from the lungs. 



E. The Superior Vena Cava, returning the blood from the arms and head to 



the right auricle. 



F. The Arch of the Aorta. 



G. The Pulmonary Artery. 



H. H. The Right and Left Carotid Artery. 



i. The Subclavian Artery. 



K. The Internal Mammary Artery. 



L. The Thyroid Artery, to the shoulder, the neck, and the thyroid gland. 



M. The Vertebral Artery . 



N. The Lungs of the right side. 



0. The Perforation of the Diaphragm, for the transmission of the inferior 



cava. 



p. The Hole by which the (Esophagus passes into the abdomen. 

 Q. The lesser Muscle of the Diaphragm. See the text, p. 344, vol. i. 

 R. s. The whole length of the Abdominal Aorta. It is seen embraced by 



the diaphragm at R, and immediately giving off the phrenic and coeliac 



arteries. 



1. The Right Phrenic Artery. 



2. 'the Left Phrenic Artery. 



3. The Root of the Coeliac Artery. 



4. 4. The Upper Mesenteric Artery. 



5. 5. The Emulgent Arteries. 



6. The Lower Mesenteric Artery. 



7. The Superior Hamorrhoidal Artery, a branch of the last. 



8. 8. The Common Iliac Arteries. 



9. The Internal Iliac. It is seen to give off the gluteal, the ischiatic, and 



the obturator artery. 



The Phrenic Arteries 



Are ramified on the concave surface of the diaphragm, and 

 are almost always two in number; they are denominated right 

 and left from their position. They commonly originate sepa- 

 rately from the aorta, but sometimes they arise in a common 



