liver, gallbladder & pancreas- 15 Flashcards
papilla
common orifice of the duodenum that the liver and pancreas excretory ducts empty into
bile
excretory product of the liver
transported via hepatic bile ducts
- greatly facilitates digestion of fats including fat soluble vitamins A, D, E, K
if there is interference with production/excretion of bile, digestion of fats is greatly impaired
gallbladder
resevoir that stores bile on its way to the duodenum
cystic duct
connects gallbladder to bile ducts
common bile duct
drains cystic ducts to the papilla of Vater
excretory process of the pancreas
a fluid rich in enzymes that digest food once they are delivered to the small intestine
largest glandular organ in the body
liver
portal veins
carry blood from abdominal organs to the liver
hepatocytes
=parenchymal cells of the liver, filter the blood before transported back to the heart via the hepatic vein
bulk of liver composed of:
hepatocytes, large epithelial cells, arranged in lobules that carry out many essential metabolic functions.
sinusoids
separate hepatocytes
channel for blood from the portal vein to percolate to the central vein
kupffer cells
mononuclear phagocytic cells within the simusoids
phagocytose particulate matter present in the blood
canaliculi
tiny
between cell membranes of adjacent hepatocytes
carry bile produced by the hepatocytes to the portal area, where they empty into epithelial-lined bile ducts
portal triad
branches of the hepatic artery
portal vein
bile ducts
blood flows into the liver through the hepatic artery and portal vein and filters into the sinusoids.
here, hepatocytes and kupffer cells remove waste products and nutrients.
waste products are metabolized by the hepatocytes.
the metabolites may be returned to the blood, stored in the hepatocytes, or converted to components of bile and excreted into bile canaliculi. bile is carried through the canaliculi back to the portal areas for excretion via the bile ducts, while the blood itself drains into central (or hepatic) veins and eventually gets carried to the inferior vena cava and back to the heart.
metabolic functions of the liver
1: production of bile salts
2: excretion of bilirubin
3: metabolism of nitrogenous substances
4: production of serum proteins
5: detoxification of drugs and poisons
bile salts
compose bile
bipolar molecules derived from cholesterol that aggregate into spherical masses or micelles
micelles
solubilize lipids in the aqueous environment of the digestive tract
prevent cholesterol from crystallizing and emulsify or dissolve dietary lipids so that they are more easily digested by lipases in the GI tract.
bilirubin
breakdown product of hemoglobin
present in excess is imparts a yellow color or jaundice to the skin, eyes and internal organs
urea nitrogen
metabolic product of hepatocytes
breakdown of dead cells produces nitrogenous products such as ammonia. liver converts these nitrogenous products to urea nitrogen and returns it to the bloodstream to be excreted by the kidney
- severe liver failure results in accumulation of ammonia in the blood
- severe kidney failure results in accumulation of urea nitrogen in the blood
cytochrome p450 (CYP)
enzyme that catalyzes the first step in the clearance of many drugs
implications for the manner in which toxins are cleared from the liver:
1: individual variation -unpredictable
2: co-administration of drugs that are cleared by the same enzyme system
3: if enzyme clearance system is impaired.
albumin
serum protein
maintains osmotic pressure and can carry non-soluble molecules such as unconjugated bilirubin in the blood
*altered albumin levlsmay indicate underlying liver injury
clotting factors
protein produced by the liver
part of the coagulation cascade
*pts with severe liver disease have problems with blood clotting and prolonged bleeding times
pancreas
exocrine and endocrine functions
long, narrow glandular organ lying horizontally in the midabdomen behind the peritoneum
pancreatic duct
runs the length of the pancreas and empties into the duodenum after going the bile duct
acini
glands that make the bulk of the pancreas
secrete digestive enzymes into the pancreatic duct.
when activated by intestinal juices, these enzymes digest carbs, fats and proteins
*amylase, lipase, and trypsin
pancreatic enzymes can be replaced nutritionally
islets of langerhans
clusters of endocrine cells scattered among the pancreatic glands
-produce insulin and other hormones
most common problem affecting accessory digestive organs
gallstones
gallstones
usually asymptomatic but can produce serious complications such as obstruction of bile flow from migration of stones into common bile duct.
20-40% of americans
1-4% symptomatic a year
tx: surgical removal of gallbladder or cholecystectomy
hepatitis
inflammation of the liver
most common liver disease
caused by infection, autoimmune diseases, drug reactions, alcohol and obesity
- some forms are acute and resolve- hepatitis A
- some forms are reversible if the offending agent is identified and avoided-alcohol and drug induced
- many are irreversible or not detected until serious injury to liver already occurred
cirrhosis
long standing inflammation leading to substantial loss of hepatocytes and severe scarring of the liver
more common cause=alcohol and hepatitis C
not reversible- results in liver failure
hepatocellular carcinoma
most common primary neoplasm of the liver
tends to arise in cirrhotic livers
most common reasons for liver transplant
cirrhosis
hepatitis C
**livers 2nd most transplanted organ after kidney
jaundice
most obvious sign of liver disaese
manifests first in sclerae
can be caused by increased hemoglobin breakdown, liver disease, or bile duct obstruction
biliary colic
severe right upper quadrant and flank pain cause by acute cholecytitis or obstruction of the biliary ductal system by stones
*pain caused by pancreatitis is usually in the upper abdomen and radiates to the back
signs and symptoms
jaundice biliary colic abdomen & back pain unintentional weight loss steatorrhea hepatomegaly
steatorrhea
passage of greasy, smelly stools that often float in toilet water
indicates malabsorption of fats
hepatomegaly
=increase in liver size
can be palpated in the lower left quadrant just inferior to the rib cage
particularly prominent in alcoholic fatty liver and metastatic disease
routine tests to check the status of the liver:
bilirubin-elevated
total protein - low serum protein
albumin- low levels-chronic liver disease
aspartate aminotransfersase (AST)-elevated w/ liver necrosis (hepatitis)
alkaline phosphatase-elevated w/ bile obstruction
blood coagulation tests- PT deficiency
enzymes produced by pancreas can be measured in serum-elevated amylase and lipase indicate acute pancreatic injury bc these leak into blood
