Vatsanontelo

Vatsanontelo, literally "abdomen cavity" in Finnish anatomy, is the abdominal cavity, the large hollow space within the torso bounded superiorly by the diaphragm and inferiorly by the pelvic brim. It contains most of the digestive organs and several related structures, and it is separated from the thoracic cavity by the diaphragm. The peritoneum lines the interior, forming the peritoneal cavity which contains a small amount of lubricating fluid. Some organs are intraperitoneal, suspended by mesenteries, while others are retroperitoneal along the posterior abdominal wall.

Major contents include the stomach, liver, gallbladder, and spleen; most of the small intestine and parts of the large intestine. The pancreas lies across the posterior wall and is largely retroperitoneal. The kidneys and adrenal glands are located in the posterior abdomen and are also retroperitoneal. The abdominal aorta and inferior vena cava traverse the cavity, giving rise to branches that reach abdominal and pelvic organs.

Anatomically, the abdominal cavity is bounded by the diaphragm above and the pelvic brim below, and communicates with the pelvic cavity through the pelvic inlet. The space is structured by peritoneal folds, such as mesenteries and omenta, which provide routes for nerves, vessels, and lymphatics and help position and suspend organs.