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.
Causes of retinal detachment are: 1  Tears or holes in the retina. 2  These may lead to retinal detachment by allowing fluid from the middle of the eye (vitreous gel) to collect under the retina. 3  A common cause of retinal tears is posterior vitreous detachment (PVD).