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Liver:
- diaphragmatic (anterior) and visceral (posterior) surfaces
- right, left, quadrate and caudate lobes
- peritoneum
- :falciform ligament: round ligament
- coronary ligament: bare area
- lesser omentum
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lecture notes
- largest lobe is the right lobe
- quadrate is anterior, caudate is posterior
- coronary ligament- connects liver to diaphragm
- round ligament/ligamentum teres,- the obliterated umbilacral cord
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porta hepatis (hilus):
- portal (hepatic) triad:
- hepatic artery (proper): branch of celiac artery----carries oxygenated blood to the liver tissues
- (hepatic) portal vein: carries nutrient rich venous blood from the digestive tract
- bile duct: carries bile from the liver
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lecture notes
- portal hepatis- where major things enter or leave liver
- 2/3 of the blood going to the liver is from the portal vein
- hepatic veins empty into the inferior vena cava (can be embedded in the liver)
- gall bladder attatched anteriorly
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histology of the liver
- functional unit: liver lobule:
- liver cells (hepatocytes) arranged in plates (cords) radiating outward from a central vein
- at periphery of lobule are portal (hepatic) triads containing branches of portal vein, hepatic artery and bile duct
- between plates are sinusoids
- blood from the portal vein (containing products of digestion) enters the sinusoids and components leave the sinusoids (which have a fenestrated endothelium) to enter a perisinusoidal space in direct contact with hepatocytes which absorb products via microvilli
- remaining blood in sinusoids enters central veins which connect to hepatic veins which connect to IVC
- Kupffer cells in sinusoidal lining are phagocytic, removing bacterial and foreign material from blood
- bile is secreted by hepatocytes into canaliculi which
- connect to the bile duct system
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lecture notes
- is divided into lobules
- triads are found at the perferee of the lobules (artery, veins and duct)
- hepadocytes (liver cells) are arranged in chords and at the center is a vein and on the out side are the triads
- arteries and veins give blood to the sinusoids (leaky capillaries) which leak into the peri sinusoidal space which is then absorbed by the hepatic cells
- in the wall of capillaries there a cooper cells which remove debris
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Biliary Ducts and Gall Bladder:
- bile leaves the liver by the right and left hepatic ducts which join to form the common hepatic duct
- from the common hepatic duct, bile can flow either to the (common) bile duct which enters the duodenum or the cystic duct which enters the gall bladder
- cystic duct has mucosal spiral fold, which keeps lumen open allowing bile to pass either way
- common bile duct joins the pancreatic duct to form the duodenal ampulla which opens to the duodenum at the duodenal papilla
- hepatopancreatic sphincter (of Oddi)
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gall bladder
- pear‑shaped muscular sac
- fundus, body, neck
- cystic duct
- stores and concentrates bile not immediately required
- for digestion
- blood supply: cystic artery
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histology of the gal bladder
- simple columnar epithelium with apical microvilli
- no muscular mucosa and little submucosa
- muscularis externa is scattered muscle fibers
- outer adventitia
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Pancreas:
- gross anatomy:
- retroperitoneal
- head lies in concavity of duodenum
- elongated body passes to left, becoming the tail which reaches spleen
- main pancreatic duct (of Wirsung) fuses with the bile duct at the hepatopancreatic ampulla which empties into duodenum
- may be an accessory duct that opens separately to the duodenum
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blood supply and venous drainage of the pancreas:
- celiac and superior mesenteric arteries supply the head
- splenic artery supplies the body and tail
- equivalent veins drain into the portal vein
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histology:
- an exocrine gland (99%) and endocrine gland (1%)
- exocrine part consists of acini which empty into small ducts that eventually connect to the main duct
- endocrine part consist of islets scattered among the acini
- the acinar cells secrete an enzyme‑rich pancreatic juice which also contains bicarbonate ions secreted by the epithelial cells of the smallest ducts
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