cavity are the lungs and a region between the lungs, calledthe mediastinum. The mediastinum separates the thoraxinto two compartments that contain the right and leftlungs. The remaining thoracic viscera—heart, esophagus,trachea, and thymus gland—are within the mediastinum.The abdominopelvic cavity, which includes an upperabdominal portion and a lower pelvic portion, extendsfrom the diaphragm to the floor of the pelvis. Its wallprimarily consists of skin, skeletal muscles, and bones.The viscera within the abdominal cavity include thestomach, liver, spleen, gallbladder, and the small and largeintestines.The pelvic cavity is the portion of the ab-dominopelvic cavity enclosed by the pelvic bones. Itcontains the terminal end of the large intestine, the urinarybladder, and the internal reproductive organs.Smaller cavities within the head include the follow-ing (fig. 1.8):1.Oral cavity,containing the teeth and tongue.
