Describe the location of the liver
Upper right quadrant of abdomen between ribs 5-10
Liver is suspended between stomach and anterior abdominal wall by what two peritoneal ligaments?
1) Lesser Omentum - bet. liver and stomach
2) Falciform ligament - bet liver and ant. abd. wall
The Lesser Omentum contains what?
Hepatic blood vessels and bile ducts
The visceral peritoneum covers the liver except for what area?
The bare area on top of the liver that is attached to the diaphragm and surrounded by coronal ligament
T or F?
The lobes of the liver (right, left, quadrate, and caudate) are separated by functional unit.
FALSE
The lobes of the liver are demarcated by blood vessels and ligaments.
The ligamentum teres is a vestige of what?
The umbilical vein, which carries blood from placenta to fetus.
What is the Porta Hepatis and what does it contain?
The “Hilium” of the liver. Contains bile ducts, hepatic artery, portal vein
What are the functions of the liver?
Macrophages (Kupffer cells) eat bacteria Metabolism (protein, fat, carb) Store vitamins and iron Detoxify drugs, hormones, etc Secrete bile
The hepatic artery brings __________ blood from the aorta via the _________ artery
oxygenated, celiac
Portal vein brings blood high in __________ and low in ___________ to the liver from the _________, _________, and ____________ veins
nutrients; oxygen; gastric, splenic, mesenteric
What kind of cells line sinusoids in the liver? What are the functions of these cells?
Hepatocytes.
They detoxify, metabolize, store iron & vitamins, etc
Hepatic veins bring blood out of the ________ portion of the liver into the ________________.
Superior
Inferior vena cava
How are hepatocytes arranged?
Hexagonal arrangement (classic lobule)
At each corner, the portal areas (triads) contain what structures?
Hepatic artery, portal vein, bile canaliculus
What lies in the middle of the classic lobule?
Central vein
What is the functional unit of the liver?
Liver acinus
Describe the relationship of structure to function in the liver acinus.
Hepatocyte efficiency depends on proximity to blood supply. An acinus includes the central area between two adjacent lobules. The innermost zone receives most O2 and nutrients. The outermost zone receives the least.
Which zone of the acinus is the primary site of detoxification of alcohol and drugs? How does this affect it?
Zone 3; Susceptible to hypoxia and toxic damage (in conjuction with lower O2 and nutrient supply)
Trace the flow of lymph through the lobule
sinusoids –> space of Disse –> channel to either thoracic duct or inf vena cava
What is portal hypertension? What symptoms does it cause?
Back pressure of blood into portal circulation due to flow obstruction. Causes varicosities in portal-caval anastomoses (eg hemorrhoids, caput medusae and esophageal varices)
How does Acites develop?
Portal htn increases lymph flow into space of Disse. Excess lymph seeps through the visceral layer of peritoneum and creates fluid build-up in the peritoneal cavity (i.e. ascites)
How does the body compensate for acites?
Drop in blood volume stimulates renal salt and water retention until blood volume is restored.
What is fatty change? How does fatty change occur in the liver?
Intracytoplasmatic accumulation of TAG.
First, hepatocytes present multiple small fat droplets around the nucleus (microvesicular fatty change). In late stages, the size of fat droplets increases, pushing the nucleus to the periphery of the cell (macrovesicular fatty change)
From wikipedia
Where does bile originate and how does it flow out of the liver?
Secreted by hepatocytes, flows through canaliculi towards bile ducts
What makes up bile?
Bile acids, phospholipids, cholesterol
Bicarbonate (also secreted from hepatocytes)
Bile pigments (bilirubin and melatonin)
What is the function of melatonin in bile?
Antioxidant. Protects the GI mucosa against the damaging effect of bile acids.
What structures meet to ultimately form the common bile duct?
Right and Left Hepatic Ducts join to form the Common Hepatic Duct which meets with the Cystic Duct from the gall bladder. Together they flow into the Common Bile Duct
Describe the structures that meet to allow bile and pancreatic secretions to flow into the sm int.
Main Pancreatic Duct = outflow from pancreas
Hepatopancreatic Ampulla = junction of Common Bile Duct and Pancreatic Duct
Major Duodenal Papilla secretes bile and pancreatic secretions into duod.
What are the parts of the gall bladder?
Body, neck, fundus, cystic duct
How is bile stored in the gall bladder? What else happens to the bile?
In fasting state, Sphincter of Oddi (major duod. papilla) is closed. Creates backflow of bile to fill gall bladder.
It becomes more concentrated due to water absorption through the mucosa.
What is involved in the release of bile from the gall bladder?
Fats trigger release of CCK which contracts g.b. wall. Vagus n. increases bile flow and contracts g.b.
What drugs are used to alter bile production?
Cholegog triggers release of bile.
Choleretics increase production (and maybe fluidity) of bile.
Describe the changes in bile flow that happen on a daily basis
G.B. has reversal of flow that happens about 4-5 hrs after last meal. The sphincter of oddi closes and bile backs up into cystic duct, which has spiral folds that create a reservoir for bile.
What is cholelithiasis? What are the symptoms?
Gall stones. Referred pain between the shoulder blades or below the right shoulder.
What is cholecystitis? What are the symptoms?
Inflammation of gall bladder. Referred pain to right scapula.
What are the functions of CKK?
Promote fat digestion by Emptying g.b. Pancreatic secretions Gastric slowing Intestinal peristalsis
What are the functions of Secretin?
Promote HCO3 secretion from
bile ducts
pancreatic ducts
Brunner’s glands
What is the primary cause of gall stones?
80% of gall stones due to cholesterol forming crystals. First sludge, then gravel, then stones.
What are other factors in the formation of gall stones?
Excess absorption of water (over concentrates bile)
Excess secretion of cholesterol
Inflammation of g.b. epithelium
Stasis of g.b. smooth muscle layer (progesterone, very low fat diet, water fast)
Reduction in terminal ileum absorption of bile salts leads to thickening of bile –> gall stones
How do lecithin and bile salts affect bile?
Both serve to increase the solubilize cholesterol. If cholesterol stays in solution –> no gall stones
