What suspends the liver between the stomach and anterior abdominal wall? What are the two ligaments?
Peritoneum - Lesser Omentum & Falciform ligament
Part 1 - Slide 2, 3
What is the largest gland (by weight) and where is it located?
Liver, upper right abdomen between ribs 5-10
Part 1 - Slide 2
Where is the less omentum located and what does it contain?
Btwn liver & stomach
Contains hepatic blood vessels & bile ducts
(Part 1 - Slide 2)
Where is the falciform ligament?
Btwn liver & anterior abdominal wall
Part 1 - Slide 3
What covers the liver except the bare area?
Visceral peritoneum
Part 1 - Slide 3
Where is the top of the liver attached to and what is it surrounded by?
Attached to diaphragm
Surrounded by coronal ligament
(Part 1 - Slide 3)
What are the lobes of the liver & what are they demarcated by?
Right, Left, Quadrate, Caudate
blood vessels & ligaments
(Part 1 - Slide 3)
What is the ligamentum teres?
Vestige of an umbilical vein carrying blood from placenta to fetus
(Part 1 - Slide 3)
What is the Porta Hepatis and what does it contain?
Hilum of the liver
Contains bile ducts, hepatic artery, & portal vein
(Part 1 - Slide 3)
How much of cardiac output does the liver receive?
29%
Part 1 - Slide 4
What are some functions of the liver?
- Macrophages consume colonic bacteria
- Metabolizes the 3 major components of food: carb, lipid, prot
- Stores vitamin & iron
- Detoxifies drugs, hormones, etc
- Secretes bile
(Part 1 - Slide 4)
What does the liver do with carbs?
Stores glucose by forming glycogen/secretes glucose into circulation through gluconeogenesis
(Part 1 - Slide 4)
What does the liver do with lipids?
synthesizes lipoproteins, cholesterol, & phospholipids
oxidizes FA
converts carbs & prot into fat
(Part 1 - Slide 4)
What does the liver do with proteins?
Synthesizes plasma proteins
Forms urea
(Part 1 - Slide 4)
Where does the hepatic artery bring blood from?
Oxygenated blood from the aorta via the celiac artery
Part 1 - Slide 5
What does the portal vein bring?
Nutrient filled deoxygenated blood from the gastric, splenic, & mesenteric veins
(Part 1 - Slide 5)
What are the sinusoids lined with? What do they do?
hepatocytes, detoxify, metabolize, store iron & vitamins
What does the hepatic vein bring blood from?
Out of the superior aspect of the liver into the Inferior Vena Cava
(Part 1 - Slide 5)
What is the classic lobule?
Hexagonal arrangement of hepatocytes
Part 1 - Slide 6
What do the portal areas (triads) at each corner contain?
Hepatic artery, portal vein, and bile canaliculus
Part 1 - Slide 6
Where does the central vein lie?
In the middle of the classic lobule
Part 1 - Slide 6
What is the more functional unit of the liver?
Liver Acinus
Part 1 - Slide 7
What does the hepatocyte efficiency depend on?
Proximity to blood supply
Of the three concentric zones incorporating portions of adjacent lobules, what does zone 1 & 3 receive?
1 - highest concentration of oxygen & nutrients
3 - least oxygen & nutrients, but is primary site of alcohol & drug detox (susceptible to hypoxia & toxic damage)
Where does plasma flow from?
Sinuosoids into space of Disse
Where is the space of Disse located?
Btwn hepatocytes & endothelium of sinusoids
Where is lymph sent to via channels?
Inferior vena cava or thoracic duct
What is portal hypertension?
Back pressure of blood into portal circulation due to flow obstruction
What are ascites?
Portal hypertension increases lymph flow into space of Disse, excess lymph seeps through the visceral layer of peritoneum & creates fluid build-up in the peritoneal cavity, drop in blood volume stimulates renal salt & water retention until blood volume is restored
Where does hepatocytes secrete bile through?
Canaliculi towards the bile ducts
What are the constituents of bile?
Bile acids, Phospholipids, Cholesterol
Bicarb (bile ducts via secretion, hepatocytes)
Bile pigments (bilirubin)
What are the biliary ducts?
R & L hepatic ducts, common hepatic duct, cystic duct, common bile duct, hepatopancreatic ampulla, main pancreatic duct, major duodenal papilla
What does the R & L hepatic duct do?
Bile outflow from liver
What does the common hepatic duct?
Junction of R & L hepatic ducts
What does the cystic duct do?
Outflow from gall bladder
What does the common bile duct do?
Outflow of bile from gall bladder & liver
What does the hepatopancreatic ampulla do?
Junction of bile & pancreatic ducts
What does the main pancreatic duct do?
outflow from pancreas
What does the major duodenal papilla do?
bile & pancreatic secretion into duodenum
What are the parts of the gall bladder?
body, neck, & fundus
How is bile stored?
Choledochal sphincter (of Oddi) creates backflow to fill gall bladder
How is bile concentrated?
mucosa absorbs water
How is bile released back into the duodenum?
CCK (released in response to fats) contracts GB wall, vagus nerve increases bile flow & contracts gall bladder
What does CCK promotes?
gall bladder emptying, pancreatic secretion, gastric slowing, intestinal peristalsis
What does secretin promote?
bicarb secretion from bile ducts, pancreatic ducts, brunner’s gland
What are gall stone precipitates of cholesterol due to?
Excess absorption of water, excess absorption of bile salts & lecithin, excess secretion of cholesterol, inflammation of epithelium, and stasis of the gall bladder smooth muscle later
What is bile necessary for?
digestion & absorption of lipids, elimination of endogenous products & exogenous substances
What is the sequence of fat digestion?
Lipases hydrolyze TG into FFA, digested fats transported to enterocytes via biliary micelles, FFA reconverted to TGs, converted to chylomicrons, transport to blood
What does bile emulsify fat into?
1 um soluble droplets
What does pancreatic lipases do?
Hydrolyze TGs to glycerides & FAs
What does Phospholipase A2 do?
hydrolyzes phospholipids
What does cholesterol esterase do?
hydrolyzes cholesterol
What is the structure of a micelle?
bile acids, phospholipids & cholesterol form lipophilic center that emulsifies fats into a form digestible by lipases
What do micelles do?
transport & facilitate absorption of glycerides & FAs through mucosa
Long chain FAs can pass through aqueous layer to reach what?
enterocyte membrane
Where do FAs, glycerides, & cholesterol go?
FA & glycerides - re-synthesized into TGs
Cholest - absorbed & processed in free form
What is enterohepatic circulation?
bile acids & salts are recycled back to the liver, most reabsorption is active transport in the ileum (less passive transport from rest of intestine), bile acids & salts are returned to the liver & reconjugated to tuarine & glycine.
What are the four types of lipoproteins?
chylomicrons, VLDL, LDL, HDL
Where are the lipoproteins produced?
Chylo - SI, VLDL - liver, LDL/HDL - plasma
What do the lipoproteins do?
Chylo - transport fat into blood, VLDL - transport TG from liver to organs, LDL - transport cholest. ester from liver to organs, HDL - transport cholest. from tissues to liver
What is bilirubin derived from?
hemoglobin (converted by colonic bacteria)
