90 ANATOMY AND PHYSIOLOGY FOR NURSES 



tricle is known as the tricuspid valve. It is composed of 

 three triangular segments, made up of a duplication of the 

 endocardium, and continuous with fine cords called the 

 cordae tendineae, which close the aperture. The valve 

 guarding the left side is composed of two irregular seg- 

 ments, and is called the bicuspid or mitral valve. If these 

 valves were to become diseased, there would be a re- 



FlG. 46. The heart (Stoney). 



gurgitation of blood into the auricle (this will be clear to 

 you if you will recollect the manner in which the blood 

 passes through the heart, as previously explained). When 

 healthy, the valves close accurately and form a complete 

 partition between the auricle and the ventricle, and the 

 blood is forced on through the large arteries. 



Each auricle is provided with openings for the arteries 

 and veins that enter from the circulation. The left 



