The 4 MAIN parts of the heart are the right atrium, left atrium, right ventricle and left ventricle.lood then flows through the  mitral valve into the left ventricle.   The left ventricle contracts to pump the blood out through  the aortic valve into the aorta (a large expandable  artery), from which blood flows out into the other arteries. . + 180 others found this useful. Lisa Frost.
Peroneal tendinitis is usually caused by repetitive use of the tendons, but can also be caused by trauma such as a rolled or sprained ankle. Little tears in the peroneus longus tendon and the peroneus brevis tendon irritate the tendon fibers resulting in pain and inflammation.
Top 10 Doctor insights on: Causes Of Focal Nodular Hyperplasia. 1 Can focal nodular hyperplasia (benign liver tumor) cause pain in the right side under the rib? Yes: If it is large enough and located in a site that would ordinary produce the pain. It can stretch the liver capsule which is quite sensitive. Gallstone disease is a more common cause of pain here and you'll probably want this ruled out; it tends to be colicky and less related to position.