General Anatomy of the Abdomen I: Part 3 PDF

15/02/24 General anatomy of the abdomen I: part 3 Learning objective: discuss the Grey’s Anatomy of the liver, pancreas and gallbladder. Functions of the liver: Removal and breakdown of toxic or potentially toxic materials from the blood. Regulation of blood glucose and lipids. Storage of certain vi...

15/02/24 General anatomy of the abdomen I: part 3 Learning objective: discuss the Grey’s Anatomy of the liver, pancreas and gallbladder. Functions of the liver: Removal and breakdown of toxic or potentially toxic materials from the blood. Regulation of blood glucose and lipids. Storage of certain vitamins, iron and other micronutrients. Synthesis of proteins and clotting factors. Metabolism of amino acids. Populated by phagocytic macrophages. Bile production. main one in this lecture The liver: Occupies the upper part of the abdominal cavity, just beneath the diaphragm. Soft, pliable organ, that should not be palpable as it lies undercover of the right costal margin. Convex upper surface is moulded to the under surface of the diaphragm. Surfaces of the liver: The liver has t wo main surfaces: 1. Diaphragmatic- anterior, superior and posterior. 2. Visceral- inferior. The diaphragmatic surface is smooth and domed, lying against the in nity surface of the diaphragm. Associated with it are the subphrenic and hepatorenal recesses. The visceral surface of the liver is covered with visceral peritoneum, except in the fossa for the gallbladder, the porta hepatis and the bare area. Structures related to it include the following: Right anterior portion of the stomach. Oesophagus. Lesser omentum. Gallbladder. Right kidney and suprarenal gland. Right colic exure and transverse colon. Gross anatomy of the liver: Divided into a left and right lobe by the fossae for the gallbladder and the IVC. Right lobe is larger. Falciform ligament ligamentum tere The quadrate and caudate lobes are described as arising from the right lobe. Functionally, however, they are said to be related to the left lobe in relation to their blood supply, venous drainage and hepatic ducts. 48 of these Couinaud segments of the liver: Each segment is wedge-shaped, apex pointing towards hepatic hilum. At apex a single segmental branch of the portal vein, hepatic artery and bile duct enter. In the sides of each segment, there is venous out ow through the hepatic veins, which run in three vertical planes that separate the segments. heart 4 8 2 5 6 Segment 4 is split into 4a and 4b. Peritoneal reflections of the liver: 2 3 4 4 8 5 6 Histology: The liver is completely surrounded by brous capsule. It is made up of liver lobules, and the central vein of each lobule is a tributary of the hepatic veins, which drains into the IVC. In the spaces bet ween the lobules are the portal canals. Portal canals contained branches of the hepatic artery , portal vein and a tributary of a bile duct = portal triad. Arterial and venous blood passes bet ween the liver cells ( hepatocytes ) by means of sinusoids and drains into the central vein. Bile: Bile acts to digest and absorb fat and fat-soluble vitamins in this small intestine and eliminate waste products, including bilirubin. It is produced and secreted by hepatocytes at a constant rate of about 40 mL per hour. Stored and concentrated in the gallbladder when digestion is not taken place. T The pancreas: tai Exocrine and endocrine gland. Exocrine portion secretes enzymes capable of hydrolysing Bod proteins, fats and carbohydrates. Endocrine portion produces the hormones insulin and glucagon, which play an important role in carbohydrate metabolism. Lies in the epigastrium. Soft, lobulated and sits on the posterior abdominal wall. Retroperitoneal ( not covered by peritoneum ) except tail. neck Head ung S Main pancreatic duct begins at the tail and runs to the head, receiving numerous tributaries. Opens into 2nd part of duodenum with the bile duct on the major duodenal papilla. Accessory duct, when present, drains upper part of the head, and opens into the duodenum, above main duct, on the minor duodenal papilla. Accessory duct frequently communicates with the main duct. Blood supply: