460 



DISSECTION OF THE THORAX. 



Base and its a short distance from the tip. The base of the ventricle is sloped, 



openings. an( j j g perforated by two apertures ; one of these, to the right and 

 below, leading into the auricle, is the right auriculo-ventricular 

 opening ; the other, on the left and much higher, is the mouth 

 of the pulmonary artery. The part of the cavity leading up to the 

 pulmonary artery is funnel-shaped, and is named the infundibulum 

 or the conus arteriosus. 



Anterior and The anterior wall, or the loose part of the ventricle, is compara- 

 tively thin, and forms most of the anterior surface of the ventricular 



posterior portion of the heart. The posterior wall corresponds with the 

 septum between the ventricles, and is much thicker. 



wall. 



FIG. 169. THE INTERIOR OF THE RIGHT VENTRICLE (FROM THE FRONT ; 

 THE HEART BEING HELD so THAT THE APEX is LOWEST DOWN). 



interior of 



is uneven 5 ; 

 on it there 



columns. 



Over the greater part of the cavity the surface is marked by pro- 

 j ec ting muscular bands, the columnce carnece ; but near the aperture 

 of the pulmonary artery the wall becomes smooth. The fleshy 

 c l umns are of various sizes, and of three different kinds. Some 

 form merely a prominence in the ventricle, especially on the septum. 

 Others are attached at each end, but free in the middle (trabeculce 

 carnece). And a third set, which are fewer in number and much 

 the largest project into the cavity, and form rounded bundles, 



