386 



The Heart. 



- Aorta asceudens 



Vena cava superior 



Site of reflection of the pericardium 



- - Coiiiis arteriosus 



Sinus transversus 

 pericardii 



Venae 

 pulmonales '^ 

 dextrae 



Atrium dextrum 



VenaVcava' inferior 



Sulcus longi- 

 tudinalis anterior 



Ventriculus dexter 



Apex cordis 



432. The heart, viewed from the right and in front, showing" 

 the place where the pericardium is reflected. 



(The hirgc arteries have been drawn away somewhat from the atria.) 

 The pericardium (see also Figs. 626631) is a serous sack, closed on all sides, which 

 presents a visceral layer, the epicardmm, firmly attached to the heart muscle, and a parietal 

 layer. Between the two layers is a small slit-like space in which are contained several grams 

 of a clear, serous fluid, the liquor pericardii. 



The epicardium (see also Figs. 411 and 412) covers completely the free surface of the 

 ventricles of the heart and contains deposits of fat of variable size along the vessels. The 

 atria are also covered on their free surface in large part by the epicardium, only the posterior 

 surface of the li>lt and a narrow strip of the right atrium remaining free from it; the v. cava 

 superior is covered by it for a distance of one little finger's bn^adth; the v. cava inferior and 

 vv. pulmonales are covered by it only at the point where they open into the heart. The 

 a. ptdmonalis and aorta ascendens are connected with one audther by connective tissue, are 

 covered in common by the eiticardium and are separated i'rom the anterior wall of the atria 

 by a slit, the sinus transversus pericardii, which is closed above and below but open to the 

 right and to the left. The epicardium is reflected into the parietal layer of the pericardium 

 along the junction between the aort;i ascendens and the arcus aortae, as well as over the 

 bifui'cation of the a. pulmonalis. 



