The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal organs, and is composed of a layer of mesothelium supported by a thin layer of connective tissue. This peritoneal lining of the cavity supports many of the abdominal organs and serves as a conduit for their blood vessels, lymphatic vessels, and nerves.
The abdominal cavity is a large body cavity in humans and many other animals that contain organs. It is a part of the abdominopelvic cavity. It is located below the thoracic cavity, and above the pelvic cavity. Its dome-shaped roof is the thoracic diaphragm, a thin sheet of muscle under the lungs, and its floor is the pelvic inlet, opening into the pelvis.
The thoracic diaphragm, or simply the diaphragm, is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm is the most important muscle of respiration, and separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity: as the diaphragm contracts, the volume of the thoracic cavity increases, creating a negative pressure there, which draws air into the lungs. Its high oxygen consumption is noted by the many mitochondria and capillaries present; more than in any other skeletal muscle.
In human anatomy, the mesentery, an organ that attaches the intestines to the posterior abdominal wall, comprises the double fold of the peritoneum. It helps in storing fat and allowing blood vessels, lymphatics, and nerves to supply the intestines.
The peritoneal cavity is a potential space between the parietal peritoneum and visceral peritoneum. The parietal and visceral peritonea are layers of the peritoneum named depending on their function/location. It is one of the spaces derived from the coelomic cavity of the embryo, the others being the pleural cavities around the lungs and the pericardial cavity around the heart.
The lesser omentum is the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach, and to the first part of the duodenum. The lesser omentum is usually divided into these two connecting parts: the hepatogastric ligament, and the hepatoduodenal ligament.
The greater omentum is a large apron-like fold of visceral peritoneum that hangs down from the stomach. It extends from the greater curvature of the stomach, passing in front of the small intestines and doubles back to ascend to the transverse colon before reaching to the posterior abdominal wall. The greater omentum is larger than the lesser omentum, which hangs down from the liver to the lesser curvature. The common anatomical term "epiploic" derives from "epiploon", from the Greek epipleein, meaning to float or sail on, since the greater omentum appears to float on the surface of the intestines. It is the first structure observed when the abdominal cavity is opened anteriorly.
The gastrocolic ligament is a portion of the greater omentum that stretches from the greater curvature of the stomach to the transverse colon. It forms part of the anterior wall of the lesser sac.
The midgut is the portion of the human embryo from which most of the intestines develop. After it bends around the superior mesenteric artery, it is called the "midgut loop". It comprises the portion of the alimentary canal from the end of the foregut at the opening of the bile duct to the hindgut, about two-thirds of the way through the transverse colon.
The suspensory ligament of the ovary, also infundibulopelvic ligament, is a fold of peritoneum that extends out from the ovary to the wall of the pelvis.
The lacrimal sac or lachrymal sac is the upper dilated end of the nasolacrimal duct, and is lodged in a deep groove formed by the lacrimal bone and frontal process of the maxilla. It connects the lacrimal canaliculi, which drain tears from the eye's surface, and the nasolacrimal duct, which conveys this fluid into the nasal cavity. Lacrimal sac occlusion leads to dacryocystitis.
The hepatoduodenal ligament is the portion of the lesser omentum extending between the porta hepatis of the liver and the superior part of the duodenum.
The mesosalpinx is part of the lining of the abdominal cavity in higher vertebrates, specifically the portion of the broad ligament that stretches from the ovary to the level of the fallopian tube.
The paracolic gutters are peritoneal recesses – spaces between the colon and the abdominal wall.
The bare area of the liver is a large triangular area on the diaphragmatic surface of the liver. It is the only part of the liver with no peritoneal covering, although it is still covered by Glisson's capsule. It is attached directly to the diaphragm by loose connective tissue. The bare area of the liver is relevant to the portacaval anastomosis, encloses the right extraperitoneal subphrenic space, and can be a site of spread of infection from the abdominal cavity to the thoracic cavity
The curvatures of the stomach are the long, convex, lateral surface, and the shorter, concave, medial surface of the stomach, which are referred to as the greater and lesser curvatures, respectively. The greater curvature, which begins at the cardiac notch, and arches backwards, passing inferiorly to the left, is four or five times longer than the lesser curvature, which attaches to the hepatogastric ligament and is supplied by the left gastric artery and right gastric branch of the hepatic artery.
The following outline is provided as an overview of and topical guide to human anatomy:
In human anatomy, the omental foramen is the passage of communication, or foramen, between the greater sac, and the lesser sac.
The pelvis is the lower part of the trunk, between the abdomen and the thighs, together with its embedded skeleton.
Peritoneal ligaments are folds of peritoneum that are used to connect viscera to viscera or the abdominal wall.
