ANGEIOLOGY, 



By G. D. THANE. 



IN this section will be included the descriptive anatomy of the heart and of the 

 principal blood and absorbent vessels. The account of the minute structure of 

 the blood-vessels and of the lymphatic vessels and glands is given in the part of 

 Volume I that treats of General Anatomy ; and the arrangement and distribution 

 of the smaller vessels within the several tissues and organs of the body are described 

 in connection with the microscopic anatomy of those parts. 



1. THE HEART. 



The heart is situated in the thorax, between the two lungs, and, together with 

 the adjacent parts of the great vessels which convey blood to and from it, is enclosed 



Fig. 304. TRANSVERSE SKCTION OP THE CHKST OP A FCETUS, PASSING IN FRONT THROUGH THE JUNC- 

 TION OP THE FIFTH COSTAL CARTILAGE WITH THE STERNUM. (Allen Thomson. ) 



The sketch represents the upper surface of the lower section ; the division is carried nearly in a hori- 

 zontal plane, s, sternum ; c, body of the eighth dorsal vertebra ; h, right, and h', left ventricle ; ce, 

 cesophagus ; pn, left pneumo-gastric nerve ; the right pneumo-gastric is behind the asophagus ; phr, 

 phrenic nerves ; a, aorta ; v a, vena azygos major ; d, thoracic duct ; 1, 1, cardiac pericardium ; 2, in the 

 anterior mediastinal space, the parietal pericardium ; 2', 2', cavity of the pericardium ; 3, 3, pulmonary 

 pleurae passing over the surface of the lungs, and reflected below their roots to form the ligamentum latum 

 pulmonis, I, I ; 3', 3', the pleural cavities ; 4, 4, parietal pleurae, reflected in front at the mediastinum 

 to the surface of the pericardium ; c, c, walls of the chest including the ribs, pectoral muscles, &c. 



