GI Mod 4 Flashcards
what divides R/L lobes of liver
Cantlie’s line
top and bottom borders of liver
IVC
gallbladder
connective tissue of liver
- falciform ligament
2. Glisson’s capsule-surrounds liver, invaginates at hilum of the liver
what is the functional unit of the liver
- hexagonal arrangement of hepatocytes and microvasculature
- at center of the hexagon is the central vein
- at each outer corner of hexagon is a portal triad
- microvasculature consists of sinusoids and bile canaliculi
what does the portal triad of liver consist of
- terminal branch of hepatic artery
- terminal branch of portal vein
- terminal bile duct
bile canaliculi drain into
terminal bile ducts
terminal bile ducts eventually drain into
R/L hepatic ducts
R/L hepatic ducts merge to form
common hepatic duct
common hepatic duct eventually divides into
- cystic duct which connects to gallbladder
2. common bile duct which descends to merge with pancreatic duct and drain into duodenum
t/f hepatocytes have ability to regenerate
true
what are 3 signaling mechanisms for liver regeneration
TGF - transforming growth factor
HGF - hepatocyte growth factor
EGF - epidermal growth factor
there is a critical ratio bw _______ _________ mass and ________ mass
funcational hepatocyte mass and body mass
fluctuations in the ratio of functional hepatocyte mass vs body mass signal what
regeneration or apoptosis
what is the duration of liver regeneration if 50-60% of liver is damaged from 4 days of tylenol overdose
completely regenerates in 30 days
hepatic circulation
- afferent pathways to liver
- sinusoids
- efferent pathway from liver
- lymphatic circulation of lymph - large production of lymph
what are the afferent pathways to the liver
- portal pathway - 75% from hepatic portal vein
2. arterial pathway - 25% from hepatic artery
what are sinusoids in liver
microvasculature within liver
what are the efferent pathway from liver
- central veins drain into hepatic veins
2. hepatic veins eventually drain into IVC
avg weight of the liver
2-3 lbs
portal pathway - hepatic portal vein
- receives blood from GI tract, spleen and pancreas
- contains large amount of nutrients from GI tract
- relatively small amount of oxygen
- divides into R/L branches and then further divides until it finally delivers blood to portal vein
portal pathway - hepatic portal anastomosis
-4 veins
collateral venous circulation with numerous veins of abdominopelvic region
- gastroesophageal vein
- rectal vein
- paraumbilical vein
- portorenal vein
portal pathway - portal HTN
portal circulation congested and reverse portal blood flow towards portal anastomoses
-occurs when cirrhosis develops
liver arterial pathway - hepatic artery
delivers oxygenated blood to liver
accounts for approx 25% of blood flow to liver
originates from celiac trunk
arterial pathway of liver - hepatic artery and portal HTN
blood flow to liver from hepatic artery is not impaired
the relative high amount of O2 delivered to hepatocytes is synergistic with regeneration