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