Answers

2015-08-31T21:47:27+05:30
In heart there are four chambers the upper parts are called atria and the lower parts are ventricels the walls of the ventriculs are relatively thicker than atrial walls the rigid vessels are called arteries which orginate from the heart nd supply blood to various organs the larger atria is arota and the smaller is palmonary atery which carry blood to lungs veins collect the blood
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