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TEXT-BOOK OF PHYSIOLOGY. 



FIG. 113. THE LEFT AURICLE AND VENTRICLE OPENED AND A PART OF THEIR 

 ANTERIOR AND LEFT WALLS REMOVED. . The pulmonary artery has been 

 divided at its commencement; the opening into the left ventricle is carried a short 

 distance into the aorta between two of the segments of the semilunar valves; 

 and the left part of the auricle with its appendix has been removed. The right 

 auricle is out of view. i. The two right pulmonary veins cut short; their open- 

 ings are seen within the auricle, i'. Placed within the cavity of the auricle on 

 the left side of the septum and on the part which forms the remains of the valve 

 of the foramen ovale, of which the crescentic fold is seen toward the left hand 

 of i'. 2. A narrow portion of the wall of the auricle and ventricle preserved 

 round the auriculo-ventricular orifice. 3, 3'. The cut surface of the walls of the 

 ventricle, seen to become very much thinner toward 3 // , at the apex. 4. A small 

 part of the anterior wall of the left ventricle which has been preserved with the 

 principal anterior columna carnea or musculus papillaris attached to it. 5, 5. 

 Musculi papillares. 5'. The left side of the septum, between the two ventricles, 

 within the cavity of the left ventricle. 6, 6'. The mitral valve. 7. Placed in 

 the interior of the aorta, near its commencement and above the three segments of 

 its semilunar valve which are hanging loosely together, f. The exterior of the 

 great aortic sinus. 8. The root of the pulmonary artery and its semilunar valves. 

 8'. The separated portion of the pulmonary artery remaining attached to the 

 aorta by 9, the cord of the ductus arteriosus. 10. The arteries rising from the 

 summit of the aortic arch. (Allen Thomson.) 



