局部解剖学结肠上区.ppt

Section 4 Peritoneum and Peritoneal Cavity,I. Introduction 1. Peritoneum is a serous membrane which lines abdominopelvic cavity, and can be likened to a slack balloon into which organs are invaginated. Parietal peritoneum lines abdominal and part of pelvic walls, while Visceral peritoneum covers viscera.,Peritoneal cavity is potential space between parietal and visceral layer of peritoneum. In male, is a closed sac; but in female, there is a communication with outside through uterine tubes, uterus, and vagina. A film of fluid lubricates surfaces of peritoneum and facilitates free movement of viscera, one against another or against abdominal or pelvic walls.,2.The most important functions of peritoneum are Absorption , Secretion and Supporting viscera. Peritoneum has capacity of absorption. Soluble substances and water are probably absorbed directly into blood. Peritoneum in subphrenic region has a greater absorptive capacity than other regions.,After abdominal or pelvic operations, it has been customary to put patient in Fowlers position, so that any inflammatory intraperitoneal effusion will gravitate into pelvis.,Fowlers position, Peritoneum may secrete a lubricating serous fluid that continuously moistens associated organs to minimize friction and to resist infection. Under certain pathological conditions, potential space of peritoneal cavity may form an actual space containing several liters of fluid. Ascites is an accumulation of serous fluid in peritoneal cavity ( hydroperitoneum )., The peritoneum surrounds and supports viscera in a number of different ways, which may be characterised as follows: mesentery, ligament, omentum, and so on.,Treatment of Renal Failure Continuous Ambulatory Peritoneal Dialysis,3. Based on covering of peritoneum, viscera in abdominal and pelvic cavities can be divided into three kinds: Intraperitoneal viscera viscera are almost completely invested by peritoneum and more mobile than,other viscera, such as spleen, stomach, small intestine, transverse colon and sigmoid colon,etc.,Intraperitoneal viscera, Interperitoneal viscera viscera are covered by peritoneum on their three aspects, such as gall-bladder, liver, ascending colon, uterus and urinary bladder., Retroperitoneal viscera viscera are covered by peritoneum only on their one aspect, such as pancreas, ureter, kidney and suprarenal gland.,Interperitoneal viscera,Retroperitoneal viscera,II. Main Contents I) Structures which are formed by peritoneum 1. Omenta are folds of peritoneum between stomach and other abdominal viscera. There are two omenta, lesser and greater.,(1) Lessor omentum two-layered fold of peritoneum which extends from porta hepatis to lesser curvature of stomach and superior part of duodenum. The portion of lesser omentum extending between the liver and stomach is named Hepatogastric ligament.,Hepatoduodenal ligament extends from porta hepatis to superior part of duodenum. Close to its right free margin the two layers of lesser omentum enclose proper hepatic artery (left anterior), hepatic portal,vein (posterior) and common bile duct (right anterior).,(2) Greater omentum consists of a double sheet, folded on itself so that it is made up of four layers. Anterior two layers descend from greater curvature of stomach and superior part of,duodenum and pass downwards like an apron in front of coils of small intestine, for a variable distance, and then turns upward themselves as far as to attach anterosuperior aspect of transverse colon.,The part between greater curvature of stomach and transverse colon is referred to as gastrocolic ligament. If an infection occurs in intestine, plasma cells in greater omentum combat infection and help prevent it from spreading to peritoneum.,(3) Omental bursa (lesser sac) lies behind stomach and lesser omentum. Its superior wall is peritoneum which covers the caudate lobe of liver and diaphragm; Inferior wall is transverse colon and its mesocolon; Anterior wall is formed by lesser omentum, posterior wall of stomach and gastrocolic ligament;,Posterior wall is formed by peritoneum covering diaphragm, pancreas, left kidney and suprarenal gland; Left wall is bounded by spleen, gastrosplenic ligament and splenorenal ligament; On the right, omental bursa communicates with greater sac through omental foramen.,(4) Omental foramen (Winslows foramen) lies behind free edge of hepatoduodenal lig. and it can admit two fingers. It is a channel between omental bursa and greater sac. Its anterior wall is formed by hepatodudenal lig.; Peritoneum covering inferior vena cava lies its behind; Caudate lobe of liver forms its roof; Superior part of duodenum is its inferior wall.,2. Mesenteries or mesocolons are two-layered fold of peritoneum that attach part of intestines to posterior abdominal wall.,(1) mesentery (of small intestine) is a broad, fan-shaped fold of peritoneum connecting coils of jejunum and ileum to posterior abdominal wall. Root of mesentery (attached border) is about 15cm long and is directed,obliquely from left side of L2 to in front of right sacroiliac joint. Intestinal border of mesentery is folded about 7 m long and contains superior mesentery vessels, lymph nodes, nerve and a certain amount of fat.,(2) Transverse mesocolon is a double fold of peritoneum which connects transverse colon to posterior abdominal wall. Between two layers are blood vessels, nerves and lymphatics of transverse colon.,(3) Sigmoid mesocolon is a fold of peritoneum which attaches sigmoid colon to the pelvic wall.,Its line of attachment has the form of an inverted V-shaped, with apex located in front of left ureter and division of common iliac a (4) Mesoappendix is a triangular fold of peritoneum and extends from terminal part of,ileum to appendix. Appendicular a. runs in free,margin of mesoappendix.,3. Ligaments are two-layered folds of peritoneum that attached the lesser mobile solid visera to abdominal wall. (1) Falciform lig. of liver is a sickle-shaped fold, extends from anterior abdominal wall (umbilicus) to live. Free border of ligament site of ligamentum teres.,(2) Coronary lig. formed by the reflexion of peritoneum from diaphragm to upper and posterior parts of right and lobes of liver. Its anterior layer is continuous with falciform lig. which divides it into left and right coronary ligaments. Its posterior layer can be followed to inferior surface of diaphragm.,The area between upper and lower parts of coronary lig. is bare area of live, this area is devoid of peritoneum and lies in contract with diaphragm. (3) Ligamentum teres (a cord-like structure) site free margin of falciform lig. and is remnant of embryonic umbilical vein. Paraumbilical veins run along either side of this lig. and empty into portal vein.,(4) Gastrosplenic lig. is a double layer of peritoneum that connects fundus of stomach to hilum of spleen. It contains short gastric and left gastroepiploic vessels. (5) Splenorenal lig. extends between hilum of spleen and anterior aspect of left kidney. The splenic vessels lies within this ligament, as well as tail of pancreas.,(6) Suspensory lig. of duodenum (Treitzs lig.) consists of suspensory muscle of duodenum and fold of peritoneum,which invests it. It lies on left side of 2nd lumbar vertebra, ascending from posterior aspect of duodenum to right crus of diaphragm. This ligament is used to identify duodenojejunal flexure.,4. Recesses In certain part of abdomen, peritoneal fold may sometimes be found which bound fossae or recesses of peritoneal cavity. These recesses are of surgical importance since they may become site of “internal” hernia.,(1) Superior and Inferior duodenal recesses They occur most commonly and are formed by folds of peritoneum stretching from ascending part of duodenum to posterior abdominal wall, left to duodenojejunal junction.,(2) Intersigmoid recess lies behind apex of inverted V-shaped attachment of sigmoid mesocolon and forms a funnel-shaped recess; its orifice opens downwards. Left ureter passes behind this recess.,(3) Hepatorenal recess lies between right lobe of liver, right kidney, and right colic flexure and is lowest parts of the peritoneal cavity when subject is supine,5. Pouches In the lesser pelvis, peritoneum dips downwards forming a large fossa, named pouch. In male, rectovesical pouch lies between rectum and urinary bladder. In the female, rectouterine pouch ( Douglas pouch ) lies between rectum and uterus, and vesicouterine pouch is formed between uterus and urinary bladder.,Rectouterine pouch in female is lowest part of peritoneal cavity in anatomical position, and rectovesical pouch in male.,When patient is operated on organs in peritoneal cavity, patient may be propped in semi-sitting position. Fluid in peritoneal cavity may descend either to relatively accessible rectovesical pouch or rectouterine pouch so that fluid in pouch may be approached surgically through rectum or vagina.,) Divisions of peritoneal cavity Peritoneal cavity is divided into supracolic and infracolic compartments by transverse colon and its mesocolon.,1.Supracolic compartments (subphrenic space )lies between diaphragm and transverse colon and its mesocolon. It includes some spaces, for example, Suprahepatic and Infrahepatic recess.,2. Infracolic compartments lies below transverse colon and its mesocolon. It has four spaces: right and left paracolic sulci (gutters), right and left mesenterial sinuses (infracolic spaces).,(1) Right paracolic sulcus (gutter) lies lateral to ascending colon. It communicates with hepatorenal recess and pelvic cavity. It provides a route for spread of infection between pelvic and upper abdominal region.,(2) Left paracolic sulcus (gutter) lies along lateral side of descending colon and opens freely into the pelvis at its lower end. It is separated above from supracolic compartment by phrenicocolic ligament.,(3) Right mesenteric sinus (right infracolic space triangular space) li