Lecture 2 Peritoneum & Abdominal Cavity PDF

Peritoneum & Abdominal cavity  Peritoneum Membrane (loose connective tissue): sac-like serous cavity – Lines abdominopelvic cavity – Surround organs 2 continuous layers – Parietal peritoneum Line internal surface abdominopelvic cavity – Visceral peritoneum...

Peritoneum & Abdominal cavity  Peritoneum Membrane (loose connective tissue): sac-like serous cavity – Lines abdominopelvic cavity – Surround organs 2 continuous layers – Parietal peritoneum Line internal surface abdominopelvic cavity – Visceral peritoneum Lines organs/viscera  Peritoneum Relationship: viscera to peritoneum – Intraperitoneal organs Almost completely covered (VP) NOT inside – just invaginated into closed sac – Extraperitoneal organs Outside of peritoneum – partially covered (VP) Kidneys Peritoneal cavity – Potential space: VP – PP – Peritoneal fluid  Mesentry Double layer of peritoneum Attaches an organ to the posterior abdominal wall Serves as continuation of visceral and parietal peritoneum Provides a means for neurovascular communication between organ and body wall  Mesentery Intraperitoneal organs – Stomach, spleen, small intestine Connected to abdominal wall – Mesentery 2 layers of peritoneum – Mesentery: jejunum & ileum – Transverse mesocolon: transverse colon – Sigmoid mesocolon: sigmoid colon – Meso-appendix: appendix Core: blood & lymphatic vessels, nerves, lymph nodes & fat  Omentum 2X layer extension/fold: peritoneum – Stomach & prox. duodenum → adjacent organs in abdominal cavity Greater Lesser  Omentum Double layer of peritoneum Attaches the stomach to the another organ Liver = lesser omentum Transverse colon = greater omentum  Lesser Omentum Greater Omentum  Greater omentum Prominent peritoneal fold – Hangs (like apron) from greater curvature stomach – Folds back (after descending) – attach to ant. surface transverse colon & its mesentery Greater omentum  Innervation Sensory innervation: inf. surface diaphragm – Phrenic nerve Inf. diaphragmatic peritoneum (central) – Intercostal nerves & subcostal nerve (T7 – T12) Inf. diaphragmatic peritoneum (peripheral) – Branches: T7 – T12 & L1 Parietal peritoneum: rest abdominal cavity Peritoneal formations  Peritoneal ligaments Falciform ligament Hepatogastric Hepatoduodenal – Portal triad (PV, pHA, BD) Gastrophrenic Gastrosplenic Gastrocolic Splenorenal  Peritoneal folds Reflection of peritoneum Raised – underlying structures – Blood vessels, ducts Lateral umbilical folds – Inferior epigastric arteries  Peritoneal folds Superior to the umbilicus Falciform ligament Round ligament of the liver (obliterated foetal umbilical vein)  Peritoneal folds Inferior to the umbilicus Reflection of peritoneum Raised from abdominal wall by underlying structure Median umbilical fold – urachus Medial umbilical fold – obliterated umbilical artery = medial umbilical ligament Lateral umbilical fold – inferior epigastric vessels Inferior Epigastric Artery Inferior Epigastric Artery Direct inguinal hernia Indirect inguinal hernia  Pouches & recesses Pouch of peritoneum formed by peritoneal folds – Duodenal recess – Caecal recesses: Superior ileocaecal Inferior ileocaecal Retrocaecal – Intersigmoid recess – Omental bursa Omental bursa Omental bursa (left subhepatic space) Omental bursa Sac-like cavity: post. to stomach, lesser omentum & adjacent structures Sup. recess: limited sup: – Diaphragm – Coronary lig. of liver Inf. recess: – Between sup. parts layers – greater omentum Omental foramen (epiploic) Omental foramen Connects greater sac (peritoneal cavity) and lesser sac (omental bursa) Omental foramen (epiploic) Omental foramen Anterior: Free border of lesser omentum: – Common bile duct (right) – Proper hepatic artery (left) – Hepatic portal vein (posterior) Omental foramen (epiploic) Omental foramen Posterior: – Inferior vena cava Omental foramen (epiploic) Omental foramen Superior: – Caudate lobe of liver Omental foramen (epiploic) Omental foramen Inferior: – 1st part of duodenum – Common hepatic artery  Omental foramen (epiploic) Summary Boundaries – Anteriorly Hepatoduodenal lig. – Posteriorly IVC & right crus of diaphragm (PP) – Superiorly Liver (VP) – Inferiorly Sup. 1st part duodenum  Division of abdominal cavity Transverse mesocolon divides abdominal cavity – Supracolic compartment Stomach, liver, spleen – Infracolic compartment Small intestine, ascending & descending colon Divided: left infracolic space & right infracolic space: – Mesentery of small intestine  Supracolic Infracolic Right Left  Paracolic gutters Communication: supracolic & infracolic compartments  Gutters Right paracolic gutter Left paracolic gutter Right, between mesentry of jejenum and ileum and ascending colon (no exit) Left, between mesentry of jejenum and ileum and descending colon (exit inferior)