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 nerve injury symptoms. Symptoms of a peroneal nerve injury, also known as peroneal neuropathy include numbness or tingling in the front and or side of the lower leg.There will be decreased sensitivity when touching these areas.ther injuries can result in nerve injury such as a fracture of the fibula or more seriously a dislocated knee. Damage can also occur during surgery. Similar symptoms may be present due to compression of the nerve at a higher level, usually either at the nerve root in the lumbar spine (L4 - S3) or in the buttocks.