Anatomy lecture 21

  1. Liver:
    • diaphragmatic (anterior) and visceral (posterior) surfaces
    • right, left, quadrate and caudate lobes
    • peritoneum
    • :falciform ligament: round ligament
    • coronary ligament: bare area
    • lesser omentum
  2. 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
  3. 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
  4. 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
  5. 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
  6. 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
  7. 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)
  8. gall bladder
    • pear‑shaped muscular sac
    • fundus, body, neck
    • cystic duct
    • stores and concentrates bile not immediately required
    • for digestion
    • blood supply: cystic artery
  9. 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
  10. 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
  11. 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
  12. 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
Card Set
Anatomy lecture 21
the end of the digestive system lectures