Abdominal organs and peritoneum By Dr N Satyanarayana

Abdomen Lower part of trunk situated below the diaphragm It is divided in to 3 parts: Abdomen proper Pelvis Perineum Abdominal cavity: Cavity situated in the abdomen It extends up in to the lower part of thoracic cage and extends down into the bony pelvis as pelvic cavity Divided into 2 parts Pelvic cavity

Abdomen proper Is the upper part of abdominal cavity Major contents: Peritoneum Parts of gastrointestinal tract – Stomach, small intestine (duodenum, jejunum and ileum), most of the large intestine (caecum, ascending colon, transverse colon, descending colon, sigmoid colon, appendix), liver, pancreas

Spleen, suprarenal (adrenal) glands, Parts of urinary system - kidneys, parts of ureters, Large vessels such as abdominal aorta, common iliac artery, external iliac and internal iliac arteries, inferior vena cava and portal vein

sigmoid colon

Urinary system Kidney Ureter Urinary bladder Urethra

Pelvic cavity Situated in the pelvis Is the lower part of abdominal cavity Major contents: Peritoneum Parts of large intestine (sigmoid colon, rectum) Parts of urinary system - urinary bladder, ureters, urethra Male reproductive organs – vas deferens, prostate, seminal vesicle Female reproductive organs – ovary, uterine tube, uterus, vagina Nerves – sacral plexus of nerves Blood vessels – internal iliac artery and vein

Male reproductive organs Bulbourethral glands

Female reproductive organs

The peritoneum

lines the walls of the abdominal and pelvic cavities General features The peritoneum is a thin serous membrane that line the walls of the abdominal and pelvic cavities and cover the organs within these cavities Parietal peritoneum lines the walls of the abdominal and pelvic cavities Visceral peritoneum －covers the organs

The relationship between viscera and peritoneum Intraperitoneal viscera Interperitoneal viscera Retroperitoneal viscera

Folds of peritoneum. Organs in the abdomen suspended by folds of peritoneum.so such organs are mobile. The peritoneal folds provide pathways for passage of vessels and nerves and lymphatics. Peritoneal folds are given various names: A)Name of the fold is made up of: prefix –meso followed by name of the organ. Example: small intestine called enteron so peritoneal fold suspending part of colon called meso-colon or mesentry.

B) large peritoneal fold attached to stomach is called omenta B) large peritoneal fold attached to stomach is called omenta.(means cover). C) Double layered fold of peritoneum connect organs to abdominal wall is called ligaments. These named after the structure they connect. Example: Gastrosplenic lig. Connect stomach to spleen. D) Some fold named according to shape: Example: Triangular ligaments of liver.

RECESS OR SMALL POCKETS. Small pockets or recess of the peritoneal cavity may be separated from the main cavity by small folds of peritoneum. These peritoneal recess or fossae are of clinical importance. Exp: internal hernia may take place in to these recess.

Peritoneal cavity －the potential space between the parietal and visceral layer of peritoneum. Between these layers there is a thin filim of serous fluid secreted by mesothelial cells.these fluid lubricating function. Peritoneal cavity divided in to two parts: Grater sac:the main larger part. Lesser sac:behind the stomach,lesser omentum, liver. To sacs communicate with each other with epiploic foramen(foramen winslow)

Sex differences. In the male, is a closed sac, lined by mesothelium. But in the female, there is a communication with the exterior through the uterine tubes, the uterus, and the vagina. Peritoneum covering Ovaries by-cuboidal epithelium. Peritoneum covering fimbria- columnar epithelium.

Peritoneal cavity Lesser sac Greater sac

Functions 1.Secretes a lubricating serous fluid that 2.continuously moistens the associated organs 3.Absorbtion and dialysis. 4.Support viscera. 5.Protection of viscera. 6.Healing power and adhesions. 7.storage of fat.

The relationship between viscera and peritoneum Intraperitoneal viscera : viscera completely surrounded by peritoneum, example, stomach, superior part of duodenum, jejunum, ileum, cecum, vermiform appendix, transverse and sigmoid colons, spleen and ovary Interperitoneal viscera－most part of viscera surrounded by peritoneum, example, liver, gallbladder, ascending and descending colon, upper part of rectum, urinary bladder and uterus Retroperitoneal viscera－some organs lie on the posterior abdominal wall and are covered by peritoneum on their anterior surfaces only, example, kidney, suprarenal gland, pancreas, descending and horizontal parts of duodenum, middle and lower parts of rectum, and ureter Intraperitoneal viscera Interperitoneal viscera Retroperitoneal viscera

Interperitoneal viscera

liver spleen

DORSAL AND VENTRAL MESOGASTRIUM AORTA VENTRAL MESOGASTRIUM COELIC TRUNK LIVER DORSAL MESOGASTRIUM SPLEEN SUPERIOR MESENTRIC ARTERY INFERIOR MESENTRIC ARTERY

Structures which are formed by peritoneum Omentum －two-layered fold of peritoneum that extends from stomach to adjacent organs

Lessor omentum －two-layered fold of peritoneum which extends from porta hepatis to lesser curvature of stomach and superior part of duodenum Hepatogastric ligament －extends from porta hepatis to lesser curvature of stomach . Hepatoduodenal ligament Extends from porta hepatis to superior part of duodenum Contains common bile duct, proper hepatic a. and hepatic portal v. Contents: right and left gastric vessels. Hepatic artery, portal vein,bile duct.

Omental foramen or Epiploic foramen or foramen winslow. Behind the right border of hepatoduodenal ligament(lesser omentum). Superior－caudate lobe of liver Inferior－superior part of duodenum Anterior－hepatodudenal ligament Posterior－peritoneum covering the inferior vena cava

Greater omentum －four-layered fold of peritoneum, the anterior two layers descend from the greater curvature of stomach and superior part of duodenum and hangs down like an apron in front of coils of small intestine, and then turns upward and attaches to the transverse colon. If an infection occurs in the intestine, plasma cells formed in the lymph nodes combat the infection and help prevent it from spreading to the peritoneum. So it is called police men of the abdomen,

Lessor omentum Greater omentum

Omental bursa Position－situated behind the lesser omentum and stomach Walls Superior－peritoneum which covers the caudate lobe of liver and diaphragm Anterior－formed by lesser omentum, peritoneum of posterior wall of stomach, and anterior two layers of greater omentum Inferior－conjunctive area of anterior and posterior two layers of greater omentum Posterior－formed by posterior two layers of greater omentum, transverse colon and transverse mesocolon, peritoneum covering pancreas, left kidney and suprarenal gland

Right－formed by omental foramen Left－formed by the spleen, gastrosplenic ligament and splenorenal ligament Right－formed by omental foramen The Omental bursa (lesser sac) communicates with the greater sac through the omental foramen. Left side Right side Spleen,gastro,splenorenal lig.

Mesenteries or mesocolons－ two-layered fold of peritoneum that attach part of the intestines to the posterior abdominal wall

Mesentery －suspends the small intestine from the posterior abdominal wall Broad and a fan-shaped Consists of two peritoneal layers Intestinal border－folded, 7 m long Radix of mesentery 15 cm long Directed obliquely from left side of L2 to in front of right sacroiliac joint

Mesentery

Mesoappendix Triangular mesentery－extends from terminal part of ileum to appendix Appendicular artery runs in free margin of the mesoappendix Mesoappendix

Transverse mesocolon －a double fold of peritoneum which connects the transverse colon to the posterior abdominal wall Sigmoid mesocolon inverted V-shaped, with apex located in front of left ureter and division of common iliac artery

Ligaments Ligaments of liver －two-layered folds of peritoneum that attached the lesser mobile solid visera to the abdominal wall Ligaments of liver Falciform ligament of liver Consists of double peritoneal layer Extends from anterior abdominal wall (umbilicus) to live Free border of ligament site of ligamentum teres

Coronary ligament －the area between upper and lower parts of the coronary ligament is the bare area of live, this area is devoid of peritoneum and lies in contract with the diaphragm Left and right triangular ligaments: formed by right extremity of coronary ligament and left leaf of falciform ligament, respectively

Hepatogastric ligament Hepatoduodenal ligament Ligamentum teres hepatis

Ligaments of spleen Gastrosplenic ligament a double layer of peritoneum that connects the fundus of stomach to hilum of spleen. In this double layer of peritoneum are the short gastric and left gastroepiploic vessels Splenorenal ligament －extends between the hilum of spleen and anterior aspect of left kidney. The splenic vessels lies within this ligament, as well as the tail of pancreas Phrenicosplenic ligament Splenocolic ligament spleen

Ligaments of stomach Hepatogastric ligament Gastrosplenic ligament Gastrophrenic ligament Gastrocolic ligament Gastropancrestic ligament

Folds and recesses of posterior abdominal wall Superior duodenal fold and recess Inferior duodenal fold and recess Intersigmoid recess －formed by the inverted V attachment of sigmoid mesocolon

Retrocecal recess －in which the appendix frequenty lies Hepatorenal recess (Morison”s pouch) －lies between the right lobe of liver, right kidney, and right colic flexure, and is the lowest parts of the peritoneal cavity when the subject is supine. It is most dependent part of abdominal cavity.Fluid tend to collect here.

Hepatorenal (Morison’s) pouch: Most dependent part of peritoneal cavity in supine position Boundaries: Anterior: Right lobe of liver, gall bladder Posterior: Right kidney, second part of duodenum, right flexure of colon, transverse mesocolon, head of pancreas Superior: Inferior layer of coronary ligament Inferior: Opens to the general peritoneal cavity Hepatorenal (Morison’s) pouch:

Hepatorenal pouch Stomach Gastrosplenic ligament Gall bladder Spleen Liver (right lobe) Pancreas Hepatorenal pouch Greater omentum Right flexure of colon Right kidney Duodenum (2nd part)

Folds and fossas of anterior abdominal wall Medial umbilical fold －contain the remnant of urachus (median umbilical ligaments) Medial umbilical fold －contains remnants of the umbilical arteries (medial umbilical ligaments) Lateral umbilical fold －contains the inferior epigastric vessels Supravesical fossa Medial inguinal fossa Lateral inguinal fossa

Pouches In male－rectovesical pouch In female Rectouterine pouch －between rectum and uterus Vesicouterine pouch －between bladder and uterus

Peritoneal subdivisions The transverse colon and transverse mesocolon divides the greater sac into supracolic and infracolic compartments. Supracolic compartments (subphrenic space)－lies between diaphragm and transverse colon and transverse mesocolon Suprahepatic recess lies between the diaphragm and live－the falciform ligament divides it into right and left suprahepatic recesses

Left suprahepatic recesses left anterior suprahepatic spaces left posterior suprahepatic spaces Right suprahepatic recesses right anterior suprahepatic spaces right posterior suprahepatic spaces bare area of live (extraperitoneal space)

Right infrahepatic recesses (hepatorenal recess) lies between the live and transverse colon and transverse mesocolon－the ligamentum teres hepatic divides it into right and left infrahepatic recesses Right infrahepatic recesses (hepatorenal recess) Left infrahepatic recesses left anterior infrahepatic space left posterior infrahepatic space

Infracolic compartments －lies below the transverse colon and transverse mesocolon Right paracolic sulcus (gutter) － lies lateral to the ascending colon. It communicates with the hepatorenal recess and the pelvic cavity. It provides a route for the spread of infection between the pelvic and the upper abdominal region. Left paracolic sulcus (gutter) － lies lateral to the descending colon. It is separated from the area around the spleen by the phrenicocolic ligament, a fold of peritoneum that passes from the colic flexure to the diaphragm.

Right mesenteric sinus －triangular space, lies between root of mesentery, ascending colon, right 2/3 of transverse colon and transverse mesocolon Left mesenteric sinus －lies between root of mesentery, descending colon, right 1/3 of transverse colon and transverse mesocolon, its widens below where it is continuous with the cavity of the pelvis