THE PEIIICAEDIUM. 



241 



(flg. 164, 5, 5). It is reflected also upon the superior veua cava (c), 

 and on the four puhnonary veins {p, p), and forms a deep recess or 

 prolonged cavity between the entrance of tlie right and left veins 

 into the left auricle. The inferior vena cava (c') receives only a 



Fk. 164. 



Fig. 164. — Semi-Diagrammatio View of the Peuicakdiuji from behind, designed 



TO SHOW THE PRINCIPAL INFLECTIONS OF THE SeRoUS SaO ROUND THE GrEAT 



Vessels (Allen Tliomson). One-half the natural size. 



The drawing is taken from preparations in which the_ heart and vessels had been 

 partially filled by injection, the pericardium inflated and dried in the distended state, and 

 the fibrous continuation on the vessels removed. By the removal of a jjortion of the 

 pericardium from behind the right and left cavities of the heart, the position of that 

 oi-gan is made apparent. A l>ent jirobe is passed witliin the pericardium from behind 

 the right auricle, in front of the vena cava inferior, to the back of the left ventricle, which 

 may indicate the place where the large undivided sac of the pericardium is folded round 

 that vein. A, posterior surface of the right auricle ; A', the same of the left ; V, right 

 ventricle ; V, left ventricle ; Ao, the upper and back i^art of the aortic arch ; 6, innomi- 

 nate ai-tery ; C, vena cava superior ; az, azygos vein ; C, vena cava inferior between the 

 diaphragm and its union with the right auricle ; c", great coronary vein ; +, cord of the 

 ductus arteriosus ;, P, the right, P', the left pulmonary artery ; p, the right, ^j', the left 

 pulmonary veins ; D, the back of the central tendon of the diaphragm ; 1, sac of the 

 pericardium as yet uninflected ; 2, portion of this on the right side which partially sur- 

 rounds the vena cava superior, the upper and lower right pulmonary veins, and the vena 

 cava inferior ; 3, the poi-tion of tlie left side which partially surrounds the vena cava 

 inferior ; 4, the portion which is extended upwards behind the left auricle, and partially 

 folds over the pulmonary arteries and veins, and which meets between these different 

 vessels the extensions of the main sac from the right and left ; o, tubular portion of the 

 pericardium which completely surrounds the aortic and pulmonary arterial trunks. 



VOL. IT. R 



