A. Thoracic cavity: lungs, heart, esophagus, trachea, thymus, and several large blood vessels that enter and exit the heart.
B. Cranial cavity: brain, meninges, and shock-absorbing fluid.
C. Abdominal cavity: stomach, spleen, liver, gallbladder, small intestine, and most of large intestine.
D. Pelvic cavity: bladder, portions of large intestine, and internal organs of reproduction.
E. Mediastinum: heart, esophagus, trachea, thymus, and several large blood vessels