48 



ELEMENTARY PHYSIOLOGY 



Fio. 17. — liEFT Side of the Heart of a Shf.ep (f.aid opf.n). 



P. y. pulmonary veins opening into the left auricle by four opcniiiprs, 

 as shown by the stj'les ; a, ;i style p;issed from auricle into vcntriclo 

 throuyh the auriculo-ventricular orifice ; b, a style passed into the 

 coronary vein, which, though it has no connexion with the left auricle, 

 is, from its position, necessarily cut across in thus laying open the 

 auricle. 



in.v. the two flaps of the mitral valve (drawn somewhat diat,''"am- 

 matically); pp, papillary muscles, belonging as Ijcfore to the part of the 

 ventricle cut away ; r, a style passed from ventricle in Ao. aox-ta ; Aoi^. 

 branch of aorta {see l'"ig. 12, Ao) ; P. A. pulmonary artery ; H. V.C. superior 

 yena cava. 



1, wall of ventricle cut across ; 2, wall of auricle cut away around 

 auriculo-ventricular orifice ; 3, other portions of auiicular wall cut 

 across ; 4, mass of fat around base of ventricle (see Fig. 12, 2). 



