LIVER AND GALLBLADER Flashcards
Produces bile
liver
stores bile
gallbladder
nutrients travel to liver via which vein
hepatic portal vein
composed by hepatocytes, kupffer cells and the sinusoids
acinus
the portal vein and hepatic artery branches terminate in the
sinusoids
blood flow in the liver
portal vein and hepatic artery drain into sinusoids
the go trough acinus to central vein
are lined by fenestrated liver sinusoidal endothelial cells with Kupffer cells interspersed onto the endothelium
sinusoids
between liver plate and sinusoids contains extracellular matrix components and hepatic stellate cells
space of disse
fxns. of the liver
detoxification
metabolism
immune fxn.
production of cholesterol
storage of micronutrients
blood sugar balance
protein synthesis
protein produced in liver that regulates blood oncotic pressure
albumin
what cells have immune fxns. in the liver
kuppfer cells
what cells produce bile in the liver?
hepatocytes
major constituents of bile
bile salts
bile pigment
cholesterol + fatty acids
phospholipids
inorganic ions
bile acids are a derivative of
cholesterol
oxidation of cholesterol forms
cholic acid
cholic acid or deoxycholic acid + glycine or taurine form
bile salts
fxns. of bile
fat digestion
neutralize gastric acid
anti-microbial
in aqueous solutions bile salts “huddle” together to form aggregates known as
micelles
causes of stones in the gall bladder
too much absorption of water from bile
too much absorption of bile acids
too much cholesterol in bile
inflammation of epithelium
Efficient intestinal reabsorption and hepatic extraction of bile acids enable an effective recycling and conservation mechanism that largely restricts bile acids to the intestinal and hepatobiliary compartments
Enterohepatic recyclin of bile
2 factors that enable enterohepatic recycling of bile?
intestinal reabsorption and hepatic recycling of bile acids
Main fx. of the enterohepatic recycling if bile is
Restricting bile acids to intestinal ana hepatobiliary compartments
Anatomic components of the enterohepatic circulation are
liver
biliary tract
gallbladder
small intestine
portal venous circulation
from I-cells in the small intestine) causes the gallbladder to contract strongly and release bile.
Cholecystokinin (CCK)
some oral drugs (antibiotics, NSAIDS, hormones, opioids, digoxin, and warfarin) undergoing EHR can
Prolong the elimination time
2 types of bilirubin
conjugated and unconjugated
Bilirubin in blood is bounded with albumin = indirect bilirubin.
unconjugated
(bilirubin glucuronide):
Bilirubin in liver is conjugated with glucuronic acid = direct bilirubin
conjugated
test to monitor liver damage
can monitor bilirubin in it’s conjugated and unconjugated form
Van den Bergh test
10 steps of bilirubin metabolism
- senescent red cells are a source of hemoproteins
- breakdown of heme to bilirubin occurs in macrophages in tissues, spleen and liver
- unconjugated bilirubin attached to albumin is transported to liver
- bilirubin is taken up by liver by diffusion and become conjugated to glucuronic acid
- conjugated bilirubin is actively secreted into bile and and then intestine
- In intestine, glucuronic acid is removed by bacteria converting into urobilinogen
- urobilinogen is reabsorbed from the gut and enters portal blood
- a portion of this urobilinogen participates in the enterohepatic recycling cycle
- remainder of urobilinogen is transported by blood to kidney , converted to yellow urobilin and excreted
- urobilinogen is oxidized by intestinal bacteria to the brown stercobilin
What gives urine its yellow color?
urobilin in kidneys
Bilirubin is a significant end product of
hemoglobin degradation
what 4 diseases need to be differentiated when bilirubin is elevated in blood?
hemolytic disorders vs. liver diseases
biliary obstructions vs. hepatic damages
Bilirubin concentration is measured by measuring the concentration of
conjugated and unconjugated bilirubin
An elevated concentration of unconjugated bilirubin points to what type of disease
excessive hemolysis
An elevated concentration of conjugated bilirubin points to what type of disease
hepatic damage or biliary obstruction
4 liver enzymes essential to monitor to see if there is liver o biliary damage
ALT (Alanine aminotransferase)
AST (Aspartate aminotransferase)
ALP (Alkaline phosphatase)
GGT (Gamma glutamic transpeptidase)
ALT (Alanine aminotransferase) and AST (Aspartate aminotransferase): elevated in
hepatic damage
ALP (Alkaline phosphatase) and GGT (Gamma glutamic transpeptidase): elevated in
biliary damage
in the exocrine pancreas, what 2 structures secrete pancreatic juice?
acinar cells
duct cells
Secrete zymogenic granules containing digestive enzymes:
Trypsinogen
Amylase
Lipase
Other pancreatic enzymes
acinar cells
acinar cells are stimulated by
CCK
Secrete large amount of bicarbonate (HCO3-)
duct cells
duct cells are stimulated by
secretin
which part of the intestines secretes hormones to stimulate pancreatic juice and bile secretion ?
small intestine
increased osmolarity, stretch, vagal nerve stimulation + the presence of amino acids and fats stimulate which hormone to be secreted from the small intestine
CCK
gastric acid stimulates which hormone to be secreted by the small intestine?
secretin
specific location of small intestine in which CCK and secretin are secreted
duodenum and jejunum
1) Stimulate Pancreatic Acini to secret digestive enzymes
2) Stimulate Gallbladder to contract to release bile
3) Inhibit Gastric motility and secretion
CCK
stimulates pancreatic duct and bile duct
secretin
components of pancreatic juice
water
bicarbonate
digestive enzymes
amylase
trypsin
lipase are
pancreatic enzymes
which pancreatic enzyme digests starch?
amylase
which pancreatic enzyme digests protein?
trypsin
which pancreatic enzyme digests triglycerides?
lipase
the complete digestion of food molecules in the small intestine requires the action of both
pancreatic enzymes and brush border enzymes of intestine
inactive form of trypsin
trypsinogen
where is trysinogen activated and by which enzyme?
activated within the small intestine by the catalytic action of the brush border enzyme enterokinase (EN)= enteropeptidase (a protease).
Most pancreatic enzymes are produced as inactive molecules
zymogens
Enterokinase converts
trysinogen to trypsin
what step is the triggering event for the activation of other pancreatic enzymes?
trypsin activation
may occur when the conditions provoke the activation of digestive enzymes within the pancreas, such as:
Alcoholism,
Gallstones,
Traumatic injury,
Infections,
Toxicosis from various drugs.
pancreatitis
Serum trypsinogen, pancreatic amylase and lipase tests can be used to monitor the health condition of the
pancreas
