The diaphragm separates the chest cavity from the abdominopelvic cavity. The diaphragm, also called the thoracic diaphragm, is responsible for the breathing process in the human body. It is made up of the peripheral muscle and the central tendon.
The wall of the chest or thoracic cavity encloses the heart, lungs, blood vessels, thymus and lower section of the esophagus. Within the thoracic cavity, there are other smaller cavities, such as the pleural and pericardial cavities. While the pleural cavity contains the lungs, the pericardial cavity surrounds the heart.
The abdominopelvic cavity consists of the stomach and organs that include the liver, pancreas, small and large intestines, spleen and gallbladder.