Case 10- Anatomy Flashcards
The Liver
It is the largest internal organ and is an intraperitoneal structure. The Liver has a big role in metabolism, removing drugs, producing bile, recycling red blood cells and storing Glycogen.
Where is the liver located
It sits within the right upper quadrant (RUQ) of the abdomen. It is inferior to the diaphragm and is protected by the thoracic cage.
Lobes of the liver
Anteriorly you have the left and right lobe. Posteriorly you have the caudate lobe, which sits next to the inferior vena cava and the Quadrate lobe which sits next to the gall bladder.
Segments of the liver
You can divide the liver into 8 segments which are different functional units
The lesser omentum and the liver
The lesser omentum attaches the stomach to the liver, it attaches to the lesser curvature of the stomach. It is made of two ligaments, the hepato-gastric ligament and the hepato-duodenal ligament.
Hepato-duodenal ligament
Made of the lesser omentum. It connects the porto-hepatis of the liver and the first part of the duodenum. It is also attached to the gallbladder and the portal triad
What are the ligaments made from
Peritoneum, the visceral peritoneum comes of the liver to connect to somewhere else
Coronary ligament
Top of the liver, attached to the diaphragm. There is a posterior and anterior coronary ligament
Right and left triangular ligament
Comes of the coronary ligament
Falciform ligament
Double fold of the peritoneum in the centre of the liver. Attached to the anterior abdominal wall
Round ligament of the liver (ligamentum teres)
Comes off the free edge of the falciform ligament. Not a ligament of the peritoneum but an embryological remnant of the umbilical vein. Posteriorly it extends next to the quadrate lobe towards the portal vein.
Ligamentum venosum
Starts where the round ligament of the liver ends and extends superiorly. Not a ligament of the peritoneum but an embryological remnant of the ductus venosus, this allowed the blood supply from the placenta to bypass the liver. It will receive its blood supply later when the heart contracts.
The bare area of the liver
Has no peritoneum attached to it, it is a potential route for spread of infection. Part of the diaphragmatic surface
Posterior to the liver
IVC, gallbladder, stomach and pancreas
Porta hepatitis
Attaches to the hepato-duodenal ligament. It is a deep transverse fissure which separates the quadrate and caudate lobes. It is the entrance/exit for vessels in the liver. It contains the portal triad.
Where the gallbladder is located near the liver?
The gallbladder sits next to the quadrate lobe of the liver
Impressions of the liver
The posterior aspect of the liver has impressions where different organs indent on it. It has the renal and suprarenal impression (right kidney), gastric impression (stomach), oesophageal impression and colic impression (transverse colon).
Blood supply to the liver
The portal vein enters the liver and leaves as the hepatic vein which connects to the inferior vena cava. The hepatic artery provides the blood supply to the liver
Portal triad
Contains the portal vein, hepatic artery proper and the hepatic bile duct.
Palpating the liver
The liver moves with the diaphragm during respiration. In inspiration you can palpate the liver
Function of Portal venous system
How all nutrients (except for fat) are transported from the GI tract to the liver
Hepatobiliary system
Anything involved with the transport and production of bile
The biliary tree
Transports bile from the liver to the duodenum
How bile drains through the liver
The Liver produces bile. The hepatocytes secrete bile into the bile canaliculi, the canaliculi drain into the small interlobular biliary ducts and then into the large collecting bile ducts of the intrahepatic portal triad which merge to form the hepatic duct.
Function of the gallbladder
Stores, concentrates and ejects bile into the GI tract
Structure of the gallbladder
Has a fundus, body and neck
Where does the gallbladder sit
It sits in a fossa on the visceral surface of the liver
Bile
Bile is made up of water, bile salts, bilirubin and biliverdin. It causes the green colour of the gallbladder. It is secreted into the duodenum where it emulsifies fats. Bilirubin and Biliverdin come from the breakdown of Heme in red blood cells.
The cystic duct- structure
Contains spiral valves which control how much bile is secreted.
Transport of bile from the liver to Gallbladder
Bile drains from the liver via the left and right hepatic ducts which join and form the common hepatic duct. Bile then drains into the cystic duct to enter the gallbladder.
Secreting bile into the duodenum
From the gallbladder bile drains via the cystic duct into the common bile duct. The main pancreatic duct joins with the bile duct so both pancreatic juices and bile are secreted into the duodenum. The bile duct and pancreatic duct join at the Hepatopancreatic ampulla. The bile and pancreatic juices are then secreted via the major duodenal papilla.
What forms the common bile duct
The common hepatic duct and the cystic duct
The major duodenal papillar
Has a sphincter to control secretion. Where the bile and pancreatic juices enter the duodenum
Positioning of the duodenum and pancreas
The duodenum is the first part of the small intestine, it is C-shaped. The pancreas sits within this C-shape
Calot’s traingle
An anatomical space which contains the right hepatic artery, cystic artery, lymph node of Lund and lymphatics. The triangle is dissected out during laparoscopic cholecystectomy (removal of gall bladder) to ligate cystic vessels. It is bounded by the inferior part of the liver, the cystic duct and the hepatic duct.
What artery does the cystic duct come of
In 75% of people the cystic duct comes of the right hepatic artery, In 25% of people it comes of the cystic artery
Pancreas
It is an accessory organ of digestion and is retroperitoneal.
Functions of the pancreas
It has an Exocrine function (pancreatic juice and enzymes) and an Endocrine function (regulates blood sugar by producing insulin).
Structure of the Pancreas
Split into the head, neck, body and tail. The Uncinate process is a projection of the head
Where the pancreas sits in the body
The head sits between the C-shape of the duodenum. The neck is superior to the vessels (portal vein, superior mesenteric artery). The tail sits in the hilum of the spleen. The splenic artery runs behind the body and tail. The body sits on the aorta.
Location of the Pancreas
The pancreas lies transversely and anterior to the L1 and L2 vertebra at the level of the transpyloric plane. It is posterior to the stomach
Endocrine function of the Pancreas
Produces hormones i.e. Insulin and Glucagon from the islets of Langerhans. There are no ducts and they are secreted directly into the blood or surrounding tissue
Exocrine function of the Pancreas
Produce Pancreatic juice’s which are rich in digestive enzymes, it is Alkaline to neutralise gastric acid. It is secreted via ducts. You have external secretion i.e. into the duodenum via the pancreatic duct.
What forms the exocrine pancreas
A compound acinar gland
How pancreatic juice moves through the Pancreas
The Acinus produces pancreatic juice which then travels to the Intercalated ducts into the Interlobular ducts. It then drains into the main pancreatic duct
Divisions of the Pancreas
The Pancreas is split into lobules which are made of Acini and intercalated ducts
Cells within the Acinus
- Pancreatic acinar cells: produce Zymogen granules (inactive enzyme precursors), contain Golgi and RER for protein production.
- Centroacinar cells modify pancreatic juice. Smaller then pancreatic acinar cells
- Duct epithelial cells: line the ducts. A continuation of the Centroacinar cells into the ducts
