peritoneum

• Peritoneum


  Glistening and slippery transparent serous membrane that lines the wall of abdominal and pelvic cavities and encloses the organs
• Peritoneum


  • Made up of outer layer of connective tissue and inner layer of mesothelium (single layer of squamous cells)
  • Contains peritoneal cavity which is invaginated by number of structures in the abdomen
  • Has 2 layers which are continuous with each other - parietal peritoneum and visceral peritoneum

  
• Parietal peritoneum


  Lines the inner surface of abdominal and pelvic walls, loosely attached to the walls by extraperitoneal connective tissue, separated from visceral peritoneum by peritoneal cavity, develops from somatopleuric mesoderm, blood supply and nerve supply is same as that of wall which it lines, supplied by somatic nerves - sensitive to pressure, pain, heat and cold, and laceration

  
• Visceral peritoneum


  Lines the outer surface of organs, firmly adherent to the organs, develops from splanchnopleuric mesoderm, blood supply and nerve supply are same as those of underlying organs, supplied by autonomic nerves - insensitive to touch, heat and cold, and laceration; it is stimulated primarily by stretching and chemical irritation, forms folds of peritoneum which connect the organs to the wall or organ to another organ

  
• Peritoneal cavity


  Is within the abdominal cavity and continues inferiorly into the pelvic cavity, potential space of capillary thinness between the parietal and visceral layers of peritoneum, contains peritoneal fluid produced by the mesothelial cells lining the peritoneum, fluid allows free movements of one organ over the other and allowing the movements of digestion, in females it communicates with the exterior of the body through the uterine tubes, uterine cavity, and vagina
• Peritoneal folds


  Folds of peritoneum that connect organ to the wall, connect one organ to the other organ, suspend the organs and allow the organ to move within the abdomen, contain fat, blood vessels, nerves and lymph vessels

  
• Omentum


  Double-layered extension or fold of peritoneum that passes from the stomach (and proximal part of the duodenum) to adjacent organs in the abdominal cavity, lesser omentum connects the lesser curvature of the stomach and the proximal part of the duodenum to the liver, greater omentum hangs down like an apron from the greater curvature of the stomach and the proximal part of the duodenum to the posterior abdominal wall

  
• Mesentery


  Fold suspending small and large intestine, the mesentery suspends jejunum and ileum, transverse mesocolon suspends the transverse colon, sigmoid mesocolon suspends sigmoid colon, mesoappendix suspends the appendix
• Peritoneal ligaments


  Consist of a double layer of peritoneum that connects an organ with another organ or to the abdominal wall, examples include gastrosplenic ligament, gastrophrenic ligament, lienorenal ligament, phrenicocolic ligament, left and right triangular ligaments, falciform ligament, superior and inferior layers of coronary ligaments

  
• Lesser omentum


  Fold of peritoneum connecting the liver to stomach and proximal part of duodenum, forms the anterior boundary of lesser sac, attachments include porta hepatis and fissure for ligamentum venosum of liver superiorly, and lesser curvature of stomach and first part of duodenum inferiorly, parts include hepatogastric ligament and hepatoduodenal ligament, right free margin forms the anterior boundary of Epiploic foramen and contains bile duct, hepatic artery, portal vein, hepatic plexus of nerves, lymphatics of liver, and right and left gastric vessels near lesser curvature of stomach

  
• Greater omentum


  Fold of peritoneum connecting stomach and duodenum to the pancreas (posterior wall of abdomen), attachments include greater curvature of stomach and first part of duodenum superiorly, and posterior abdominal wall inferiorly, has anterior 2 layers and posterior 2 layers with lesser sac situated between them, anterior 2 layers descend from greater curvature and posterior 2 layers ascend upwards, contents include fat, right and left gastroepiploic vessels, macrophages (milky spots), functions as a storehouse of fat and prevents the spread of infection

  
• Mesentery


  Peritoneal fold which suspends the coils of jejunum and ileum of small intestine from posterior abdominal wall, has attached border (root) 15 cm long attached to posterior abdominal wall and free (intestinal) border 6 meters long enclosing the ileum and jejunum, contents include jejunal and ileal arteries and veins, lymph nodes, lymphatics and nerves of jejunum and ileum, connective tissue and fat

  
• Mesoappendix


  Fold of peritoneum which suspends the vermiform appendix from the mesentery, contains arteries, veins, nerves and lymphatics of appendix
• Transverse mesocolon


  Fold of peritoneum which suspends the transverse colon from the upper part of posterior abdominal wall (pancreas), contains middle colic artery and vein, nerves, lymph nodes and lymphatics of transverse colon

  
• Sigmoid mesocolon


  Triangular fold of peritoneum which suspends the sigmoid colon from the pelvic wall, contains sigmoid arteries and veins, nerves, lymph nodes, lymphatics of sigmoid colon
• Gastrosplenic ligament


  Connects the stomach and spleen, contains short gastric vessels and left gastroepiploic vessels
• Lienorenal (splenicorenal) ligament


  Connects spleen and left kidney, contains splenic vessels and tail of pancreas
• Falciform ligament


  Connects the liver to the diaphragm and anterior abdominal wall, its free margin contains ligamentum teres and paraumbilical veins
• Lesser sac


  Part of peritoneal cavity situated behind the lesser omentum and stomach, lower part lies within the greater omentum, communicates with the greater sac through the epiploic foramen, located behind the liver, lesser omentum, stomach and anterior 2 layers of greater omentum
• Epiploic foramen


  Foramen connecting lesser and greater sacs, situated behind the right free margin of lesser omentum, boundaries include right free margin of lesser omentum containing portal vein, hepatic artery and bile duct anteriorly, inferior vena cava posteriorly, caudate process of liver superiorly, and first part of duodenum inferiorly, clinical significance includes internal hernia

  
• Supracolic and infracolic compartments

  Transverse colon and transverse mesocolon divide the peritoneal cavity into supracolic and infacolic compartments, supracolic compartment is divided into right and left subphrenic spaces, right and left subhepatic spaces, with left subhepatic space also known as lesser sac and right subhepatic space also known as hepatorenal (Morison's) pouch
• Rectouterine pouch (pouch of Douglas)


  Most dependent part of peritoneal cavity in females in upright position, boundaries include uterus and upper part of vagina anteriorly and rectum posteriorly, contents include coils of ileum and sigmoid colon
• Uterovesical pouch


  Situated between the uterus and urinary bladder
• Rectovesical pouch


  Lowest part of peritoneal cavity in males in upright position, boundaries include urinary bladder and seminal vesicle anteriorly and rectum posteriorly