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.
â¢ Sciatic pain (both axial and appendicular), including piriformis syndrome, since the sciatic nerve and piriformis are close neighbors. â¢ Peroneal pain and numbness, as the pudendal or cutaneous nerves can become entrapped within the sacrotuberous ligament, or between it and the sacrospinous ligaments.â¢ Painful sitting, hamstring tendinitis, or ischial bursitis. Sacroiliac joint hypermobility, hypomobility, and pain. When one sacrotuberous ligament is tighter than the other, it can be associated with sacral rotation, side bending, or fixation. â¢ Coccyx (tailbone) injuries and pain, since the sacrotuberous ligament attaches to and stabilizes the coccyx.