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.
Peroneal neuropathy refers to an impairment of the peroneal nerve. It is the most common neuropathy of the lower extremities. The common peroneal nerve is the most common nerve in the body to be injured as the result of trauma. It can be injured by trauma to the knee or to the thigh.