Anatomy of Abdomen Part 1- Peritoneum

What's in the portal triad?

-Common bile duct -Hepatic portal vein -Hepatic artery proper

What are the peritoneal ligaments of the liver?

1. Coronary ligament (a.k.a. left/right triangular ligaments) 2. Falciform ligament 3. Round ligament of liver (a.k.a. ligamentum teres hepatis) 4. Hepatogastric ligament (a.k.a. membranous lesser omentum) 5. Hepatoduodenal ligament (a.k.a. thick edge lesser omentum)

Blood flows INTO the liver via what two structures?

1. Hepatic artery proper 2. hepatic portal vein

What are the peritoneal ligaments of the stomach?

1. Hepatogastric ligament 2. Gastrophrenic ligament 3. Gastrosplenic ligament (a.k.a. gastrolienal ligament) 4. Gastrocolic ligament

Where are two sites (in SUPINE POSITION) where inflammatory exudate tends to collect?

1. Hepatorenal recess 2. Right posterior subphrenic space

What are the three types of peritoneal recesses?

1. Paracolic gutters- 2. subphrenic spaces- anterior and posterior 3. hepatorenal recesses- between liver and RIGHT kidney

Peritoneal cavity divisions?

1. greater sac 2. lesser sac

What are the abdominal structures associated or derived from the peritoneum?

1. mesentery 2. omenta 3. peritoneal ligaments 4. peritoneal recesses 5. peritoneal fossae

Name and describe the two categories of retroperitoneal.

1° - Structures that are retroperitoneal from the start of their development. 2° - Structures that were once suspended within the abdominal cavity by mesentery but migrated posteriorly behind the peritoneum.

What are the peritoneal ligaments of the spleen?

2. Gastrosplenic ligament 2. Splenorenal ligament

What is bad about peritoneal adhesions (what do they limit)?

Adhesions limit the normal movement of viscera and could lead to complications aka intestinal obstruction (volvulus) or chronic pain

What are the boundaries of the omental foramen?

Anterior border: Hepatoduodenal ligament • The free edge of the lesser omentum • Contains the portal triad: -Common bile duct -Hepatic portal vein -Hepatic artery proper 2. Posterior border: Inferior vena cava & the right crus of the diaphragm 3. Superior border: Caudate lobe of the liver 4. Inferior border: 1st part of the duodenum

Define ascites.

Ascitic fluid - excess fluid in the peritoneal cavity

What is peritoneal fluid made up of?

Composed of water, electrolytes and substances derived from interstitial fluid in adjacent organs = in healthy individual approx. 50ml

Describe the direction of ASCITIC fluid flow.

DRAINS away from liver.

Define peritoneal ligaments.

Defined as a membranous fold (a.k.a. double layer of peritoneum) that supports an organ by helping to keep it in anatomical position.

Define what is meant by an intraperitoneal organ.

Defined as being almost entirely wrapped in visceral peritoneum while being suspended (usually by mesentery) in the abdominal cavity.

Define what is meant by an infraperitoneal organ.

Defined as being beneath the peritoneum with only its superior surface covered by parietal peritoneum.

Define peritoneal recesses.

Defined as potential spaces in the abdominal cavity where excess fluid may collect.

Define peritoneal fossae.

Depressions in the anterior abdominal wall that are lateral to the three respective umbilical folds.

Define dialysis.

Dialysis is defined as the separation of particles in a liquid on the basis of differences in their ability to pass through a membrane

Where is dorsal mesentery found at?

Dorsal mesentery: -Extends continuously from the foregut to the end of the hindgut. -Dorsal mesentery is pulled towards the left side of the body! Associated with the posterior abdominal wall

Define the lesser omentum and what its subcategories are (2)

Double- layered peritoneal fold. Can be divided into TWO LIGAMENTS: 1. hepatogastric 2. hepatoduodenal (contains portal triad)

Define omenta.

Extensions of peritoneum that form ligamentous "aprons" that extend from the stomach & proximal duodenum to adjacent organs.

Define peritoneal adhesions.

Fibrous bands that form abnormal connections: visceral peritoneum attaching to an adjacent organ or visceral peritoneum attaching to parietal peritoneum (of the abdominal wall).

Describe the direction of peritoneal fluid flow.

Flow of normal peritoneal fluid is UP TOWARDS THE SUBPHRENIC SPACES.

What do peritoneal adhesions form as a result of?

Form as a result of damage (acquired through injury, infection or surgery) to the peritoneal surface when sticky fibrin appears in order to assist with the healing process.

What is the greater omentum? What does its structure allow it to do?

Four layered peritoneal fold; hangs down and is able to move within the peritoneal cavity

What is the"abdominal policeman" and what does this mean?

Greater omentum; can wrap around organs to localize inflammation and prevent peritoneal adhesions. Spans greater curvature of stomach to the anterior surface of the transverse colon.

Where does inflammatory exudate collect in the inclined position?

In the pelvic cavity where there is a slow absorption of toxins.

What's peritonitis?

Infection can occur if gas, fecal matter or bacteria enter the peritoneal cavity which would result in inflammation of the peritoneum

Differences between inflammation of parietal versus visceral peritoneum?

Inflammation of PARIETAL peritoneum: Sharp, well-localized pain Tenderness on palpation Inflammation of VISCERAL peritoneum: Generalized, referred pain that is felt in the associated dermatome of the organ

What is fibrin?

Insoluble, elastic protein that becomes replaced with fibrous scar tissue.

What shares the neurovasculature with visceral peritoneum? What can the pain in visceral peritoneum be described as?

Invests abdominal organs; served by the same neurovasculature of the RESPECTIVE organ its covering. Pain is generalized (referred to dermatomes)

What can be determined about liver injury in relationship to the Pringle Maneuver?

It can determine the extent of trauma in patients with liver injury. • If a patient is still bleeding internally after clamping, there must be a hemorrhage elsewhere which could be from: (Right or left) Hepatic veins (Retrohepatic) Inferior vena cava

What is the embryonic origin of peritoneum?

Lateral plate mesoderm.

The lesser sac extends from what structures? Are there organs in this sac? What is the lesser sac in front of and behind?

Lesser Sac: Also known as the omental bursa Remember NO organs here either! Forms due to the twisting and rotation of the gut. Small compartment that is lined with peritoneum and is positioned: Behind → Stomach & greater omentum In-front of → Peritoneum & pancreas

Greater sac extends from what? Are there organs in this sac?

Main compartment! Extends from the: 1. Diaphragm 2. Pelvis Remember NO organs are in this potential space!

Difference of Greater sac between males and females?

Males = peritoneal cavity is completely closed Females = there is an opening in the peritoneum through the uterine tubes: Infectious (or foreign) materials can travel from the pelvis into the abdominal cavity!

What is inside of the peritoneal cavity? What does the cavity allow for?

Normally is a "potential space" between the parietal and visceral layers of peritoneum and these surfaces are separated by peritoneal fluid → Enables peristaltic movements

What's a paracentesis?

Paracentesis - surgical puncture of the peritoneal cavity for the aspiration/drainage of ascitic fluid

What is an omental bursa herniation? What's needed to fix this?

Part of the gastrointestinal tract (usually a loop of the small intestine) can pass through the omental (epiploic) foramen and become twisted and strangulated inside the lesser sac; type of internal abdominal hernia NEED RAPID SURGERY TO REPOSITION AND FREE THE TRAPPED INTESTINAL TRACT.

Define peritoneum

Peritoneum is defined as the serous membrane lining the cavity of the abdomen (parietal peritoneum) and covering the abdominal organs (visceral peritoneum).

Function of mesentery?

Provide pathways for vessels, nerves, and lymphatics to pass between abdominal organs. Mesentery helps to provide a continuous connection between the visceral and parietal peritoneum Contains fat as well as the arteries, veins, lymphatic Jejunum vessels, and nerves that supply the abdominal organs Also functions to connect organs to the posterior Mesentery proper (cut) Sigmoid mesocolon Arcuate line abdominal wall

What organs are infraperitoneal?

Rectum: distal 2/3rds Urinary bladder

Define what is meant by a retroperitoneal organ.

Retroperitoneal organ: Defined as lying behind the peritoneum with only part of its surface wrapped in peritoneum.

What shares the neurovasculature with parietal peritoneum? What can the pain in parietal peritoneum be described as?

Served by the same neurovasculature as the ADJACENT wall/region! Pain is well localized (sensitive to pressure)

What is the purpose of the Pringle Maneuver?

Technique to minimize blood loss during hepatic surgery by clamping the blood vessels entering the liver (entering through the porta hepatis or hilum of the liver)

What is peritoneal dialysis in the case of renal failure?

The peritoneum is a semipermeable membrane which permits relatively rapid absorption of solutions • Solutes and water diffuse between blood in the vessels and the peritoneal cavity as these two fluid compartments have a concentration gradient. In the case of renal failure: A dilute, sterile solution can be introduced into the peritoneal cavity on one side of the patient Excess water and soluble waste products (e.g. urea) can be transferred from the blood vessels The dilute solution and waste products can be drained out of the peritoneal cavity from the other side

What structures are important in the Pringle Maneuver?

The portal triad travels within the hepatoduodenal ligament and this can be clamped to control bleeding.

The ventral mesentery is formed from what? What exactly is ventral mesentery?

The ventral mesentery is formed from the septum transversum - ventral mesentery is a mass of mesenchyme below the diaphragm and between the stomach and ventral (anterior) body wall

What are paracolic gutters? What do they allow for?

Type of peritoneal recesses; groove or space between the posterolateral abdominal wall and lateral aspect of ascending or descending colon. Free communication is able to occur between the SUPRACOLIC and INFRACOLIC regions of the greater sac.

Where is ventral mesentery found at?

Ventral mesentery: Only found between the foregut and the upper portion of the duodenum. Ventral mesentery is pulled towards the right side of the body! Associated with the liver & lesser curvature of the stomach

Define mesentery.

defined as a double layer of peritoneum resulting from the invagination of the peritoneum by organs

What does the peritoneum consist of?

mesothelium = layer of simple squamous epithelial cells, which can transform into fibroblasts Clinical correlation for peritoneal adhesions.

What is the omental foramen/epipoloic foramen?

opening that provides a direct communicaiton between the greater and lesser sacs.