Bile Flashcards
What are the layers of the gall bladder?
Mucosa, tunica muscularis and adventitia
Mucosa of gall bladder
Simple columnar epithelia, basement membrane and lamina propia
Tunica muscularis of gall bladder
Smooth muscle, connective tissue and nerves
Adventitia
Connective tissue layer connecting gall bladder to the liver. The connective tissue not in contact with the liver is the mesothelium and is loose.
Common site of gallstone formation
Hartmann’s pouch is a patch of mucosa in the neck region of the gall bladder where gallstones commonly form and get lodged, leading to cholestasis.
What is a gallstone?
Gallstones are formed of Cholesterol, calcium and biliverdin. It is mainly cholesterol due to diet or issues with hepatic metabolism.
Symptoms of cholelithiasis
Biliary colic pain in the upper right quadrant which spreads to the right shoulder. Nausea, loss of appetite and intolerance to fatty foods.
What is bilirubin?
A bile pigment formed by haemolysis.
What are the types of bilirubin?
Unconjugated bilirubin which is insoluble and conjugated bilirubin which is soluble.
Reticuloendothelial cells
Phagocytic cells such as endothelial cells and Kupffer cells in the liver.
Bilirubin synthesis
Reticuloendothelial cells such as Kupffer carry out haemolysis to produce iron and unconjugated bilirubin. This must be bound to albumin for transport in the bloodstream.
Bilirubin conjugation
Once in the liver, unconjugated bilirubin undergoes glucorinidation by glucorynyl transferase to form conjugated bilirubin, which is soluble and can be excreted with bile out the common hepatic duct and eventually enter the duodenum.
Bilirubin excretion
Bacteria in the small intestine deconjugates bilirubin. Unconjugated bilirubin -> urobilinogen, a brown-yellow bile pigment.
Excretion
Most of urobilinogen is oxidised into stercobilin and excreted into the faeces. Lesser proportion is recycled via enterohepatic circulation back to the liver to be recycled as bile.
Low/no urobilinogen in the blood
Obstruction of the gall bladder
High urobilinogen
Haemolytic anaemia
Symptoms of liver disease
Nausea/vomiting, loss of appetite, jaundice, dark coloured urine and light coloured stool.
What makes faeces brown?
Bilirubin
Dark urine and pale stools
Liver disease. Bilirubin is excreted into the urine. It is not converted to urobilinogen -> stercobilin to give faeces its brown colour
Tail of pancreas
End of the pancreas on the left side of the body which ends near the spleen
Clusters of pancreatic endocrine cells
Islets of Langerhan
Pancreatic epithelia
Simple columnar epithelia mainly with stratified columnar and stratified cuboidal
Septa
Collagenous capsule surrounding the pancrees which forms lobules. Contains digestive enzymes rather than RBC.
Septa
Collagenous capsule surrounding the pancrees which forms lobules. Contains digestive enzymes rather than RBC.
