The abdomen is the section of the body located below the chest and above the hips. It is divided into two cavities, the abdominal cavity and the pelvic cavity, by the diaphragm muscle. The abdominal cavity is surrounded by the abdominal wall, which is made up of skin, fascia (connective tissue), and muscles. Any structures that pass between the thoracic and abdominal cavities, such as the esophagus and diaphragm, will also pass through the diaphragm. The diaphragm plays an important role in regulating the pressure in the thoracic and abdominal cavities and is connected to various muscles in the body, including the coccygeus muscle. The diaphragm also has an impact on the digestive, respiratory, and cardiovascular systems. In addition, the esophagus, a muscular tube that carries food from the mouth to the stomach, runs through the diaphragm and is divided into three parts: cervical, thoracic, and abdominal. The abdomen also contains the sigmoid colon, which passes through the psoas muscles and is supported by the sigmoid mesocolon, as well as the rectum. Overall, the abdomen is a vital part of the body responsible for digestion and other important bodily functions