The digestive organs are housed by the abdominopelvic cavity of the body. These organs are lined with serous membranes - the same membranes that cover the abdominal cavity. These membranes are formed by simple squamous epithelium which are filled with connective tissues. The serous membranes are primarily responsible for secreting enough fluid lubrication for the purpose of digestion.
The serous membranes have two segments - the visceral segment (which house the internal organs) and the parietal segment (which line the body wall). The serous membranes that take care of the lungs are called pleurae, and those that look after the abdominal cavity are called peritoneum (or peritoneal membranes). The parietal peritoneum line the whole abdominal cavity. The parietal peritoneum folds over itself, creating an existential fold near the back wall of the abdominal cavity. This is where the mesentery is found. The mesentery provides support to the gastrointestinal tract, and allows the small intestine to move freely. This is also what the vessels and the nerves use for passage.
A portion of the mesentery is dedicated to serving the large intestine, and it’s called the mesocolon. This is where the peritoneal peritoneum continues to the visceral peritoneum, starting from the large intestine. The space between these two peritoneum is known as the peritoneal cavity. Next to the parietal peritoneum is where the organs the abdominal aorta, the kidneys, the pancreas and the duodenum and the colon are found. Several extrusions from the parietal peritoneum exist to aid organs in suspending from or anchoring into the peritoneal cavity.
A serous membrane composed of connective tissue known as the falciform connects the liver to the abdominal cavity. The stomach is connected to the transverse colon by the greater omentum (which also protects the small intestine). The greater omentum oversees the following necessary functions: storage of fat, support to several lymph nodes, protection in case of infections, and provision of a cushioning for the visceral organs. The greater omentum is also in charge of isolating an affected area when a serious but localized inflammation, like appendicitis, occurs. Its counterpart, the lesser omentum is found along the curve of the stomach and continues up to the upper duodenum and stops at the inferior part of the liver.