GIT Flashcards
(38 cards)
Enzyme present in saliva
Ptyalin
Defecation observed immediately after a meal in children is
Gastrocolic reflex
Digestion of proteins occur in
Dudodenum, jejunum
Functions of bile
*Digestion and absorption of fats
*bile pigments - major excretory products of bile
*bile salts acts as laxative
*Inhibits growth of cholerectic and cholagogue bacteria
*maintenance of pH
*lubricates chyme in intestine
* prevents gall stone formation
Steatorrheod
*Bulky , foul smelling, pale greasy stools
*FAT CONTENT INCREASED
*deficiency of pancreatic digestive enzymes affecting fat metabolism seen in chronic pancreatitis
Jaundice define
Raised levels of bilirubin
Yellow discoloration of skin and mucous membrane
Types and causes of jaundice
Hemolytic jaundice (pre-hepatic)
Hepatocellular jaundice (hepatic jaundice )
Obstructive jaundice (post-hepatic )
Causes of pre hepatic jaundice ( flowchart )
*Increased breakdown of RBCs
*Hemolytic disease of newborn
*hereditary spherocytosis
*malaria
*sickle cell anemia
*snake bite
*Mismatched blood transfusion
Symptoms and signs of hemolytic jaundice
*Unconjugated bilirubinemia
Hemolytic anemia
*Fecal stercobilinogen^( dark brown stools )
*urinary urobilinogen ^
*urine bilirubin normally absent
* vandenberg’s test - indirect positive
* liver function test is normal
Symptoms and signs of hepatocellular jaundice
- conjugated , unconjugated bilirubinemia
*fecal stercobilinogen v
*Urinary urobilinogen v
*Urine bilirubin present
*liver function test impaired - vandenberg’s test biphasic ( direct and indirect positive)
Signs and symptoms of obstructive jaundice
*Conjugated bilirubinemia ^
* fecal stercobilinogen- absent (clay stools )
Urinary urobilinogen
*urine bilirubin increases ( dark urine )
*vandenberg’s test - positive
* normal liver func test
Impaired in later stages
*fecal fat content ^
Causes of hepatic jaundice
Liver cannot conjugate bilirubin efficiently
*infective ( bacteria / viral hepatitis)
*toxic liver damage
* cirrhosis
Cause of obstructive jaundice
Conjugated bilirubin cannot flow thro the biliary tract freely
*cholestasis
* biliary cirrhosis
* gall stones
* carcinoma head of pancreas
Enterohepatic circulation
(Diagram )
* recirculating of bile salts from the liver to the small intestine and back again
Advantages of enterohepatic circulation
- limited pool of bile salts available for fat digestion& absorption, enterohepatic circulation is necessary
*total circulating pool of bile salts 3.6gm
*required bile salts during each meal 4-8gm - bile salts circulate twice during digestion of each meal
*approx 6-8 times per day
Clinical significance of entero hepatic circulation
Conditions that interrupt entero hepatic circulation (ileal resection , Crohn’s disease )leads to malabsorption of fats
Define peptic ulcer
Excoriated area of stomach or intestinal mucosa caused by the digestive action of gastric juice or upper small intestinal secretion .
Where the ulcer frequently occur
Lesser curvature of the antra, end
Peptic ulcer in stomach +gastric ulcer
In duodenum- duodenal ulcer
The auto digestion of the mucosa is prevented by .
Mucosal protective mechanism
- Mucosal barrier
2.bicarbonate secretion
3. Epithelial barrier
4.Trifoil peptides
5.PGE2
What is PGE 2
Can help in the synthesis of mucus and formation of new mucosal cells . Of there is injury in the gastric mucosa , dead cells can be speed.y replaced
Trifoil peptides in mucosal protective mechanism
TP in the mucosa of stomach are acid resistant and protect stomach
Epithelial barrier in MPM
Intercellular tight junction provide barrier to back diffusion of H+
Bicarbonate secretion in MPM
Between the mucus and epithelium some bicarbonate rich fluid is present .
Within lumen pH is low (2.5) , pepsin very active digest proteins easily .
Near epithelium bicarbonates present , increases pH , lesser activity of Pepsin.
This hco3- cannot ,I’ve towards lumen because of unstirred layer
Why can’t Pepsin and other gastric glands come in contact with the musosal epithelium
Because mucus of the unstirred layer acts as a barrier
