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.
In proliferative retinopathy, new, structurally unstable blood vessels grow on the surface of the retina. These unstable blood vessels cause frequent minor bleeding. The bleeding causes local irritation and scarring.Proliferative retinopathy can cause retinal detachment. This is a separation of the layers of the retina. It is one of the most serious consequences of proliferative retinopathy.The vitreous is the clear gel between the lens and the retina.