GI System and Pathology Flashcards
what is a mallory weiss tear
a tear in the tissue of the lower oeseophagus
how does a mallory weiss tear present
haematoemesis of bright red or coffee-ground blood, blood in stool, difficulty swallowing, painful swallowing, anaemia, dizziness, shortness of breath, abdominal or chest pain
what causes a mallory weiss tear
violent coughing, retching, vomiting or straining, hiatal hernia, childbirth
mallory weiss tear diagnosis and treatment
diagnosis- stool test, upper GI endoscopy
treatment- stops on its own most of the time, surgical repair (rare)
what is the function of hydrochloric acid in the stomach
antibacterial, converts pepsinogen into pepsin, chemical digestion
what is the function of gastrin hormone in the stomach
in the gastric juice which undertakes chemical digestion. stimulates parietal cells to secrete more acid
what is pancreatitis
inflammation of the pancreas, can be due to biliary obstruction or alcoholism
how does pancreatitis present
pain in epigastrium and left upper quadrant of abdomen, nausea and vomiting, tenderness on palpation, reduction in bowel sound, fever
what causes pancreatitis
gallstones, excessive alcohol, dietary factors
what effects does pancreatitis have on the body
biliary obstruction- stone obstructs bile duct which causes bile and pancreatic juice to mix and backflow into the pancreatic tissue, this causes inactive proteases to become activated and start auto-digestion of pancreatic tissue, leading to oedema and ischemic injury to the pancreatic tissue
alcohol- intracellular activation of proteases enzymes, activation of proteases leads to auto-digestion of pancreatic tissue and pancreatitis
what does pancreatic juice consist of
water, mineral salts, amylase, lipase, proteases, nucleases, trypsinogen, chymotrypsinogen
alkaline, pH8
what secretes pancreatic juice and where does it go to
secreted by exocrine pancreas and enters the duodenum
what stimulates secretion of pancreatic juice
when acid chyme from the stomach enters the duodenum, it stimulates the release of secretin and CCK, produced by enteroendocrine cells in the wall of the villi which stimulates the secretion of pancreatic juice
what is the function of pancreatic juice
when acidic stomach contents enter the duodenum, they are mixed with pancreatic juice and bile from the liver, raising the pH to 6-8 as this is the pH at which pancreatic enzymes work most effectively
what does bile consist of
water, mineral salts, mucus, bile salts, bile pigments (bilirubin), cholesterol, pH8
where is bile produced and where is it stored
produced in the liver and stored in the gallbladder
function of bile
emulsification of fats in the small intestine, making cholesterol and fatty acids soluble, enabling their absorption, excretion of bilirubin
what is cirrhosis
fibrosis (scarring) of the liver caused by long term liver damage
how does cirrhosis present
fatigue, nausea, weight loss, jaundice
causes of cirrhosis
long term liver injury, excessive alcohol consumption, hepatitis
effects of cirrhosis on the body
chronic liver inflammation causes necrosis and over time liver tissue is replaced by fibrous tissue. this blocks blood flow through the hepatic portal system, leading to portal hypertension, excess blood due to hepatic portal vein draining into small veins of GI tract, leads to oesophageal varices
what are gallstones
stones that form when the composition of bile changes
how do gallstones present
high temp, pain, jaundice, confusion
what causes gallstones
increasing age, female sex, obesity, several pregnancies in young women, diabetes
effects of gallstones on the body
composition of bile changes, decreasing the solubility of its constituents. inflamed gallbladder absorbs water and bile components at a faster rate. this can exceed the solubility of the cholesterol within the gallbladder, causing it to precipitate and form gallstones
what is appendicitis
swelling of the appendix when it becomes inflamed
how does appendicitis present
pain- generalised then moves to right lower quadrant, nausea and vomiting, diarrhoea, fever
causes of appendicitis
nobody really knows- inflammation to appendix
effects of appendicitis on the body
appendix swells, mucosal secretions increase intraluminal pressure, pressure exceeds capillary perfusion causing venous and lymphatic obstruction, reduced perfusion leads to necrosis/perforation
what is peritonitis
complication of appendicitis, inflamed peritoneum
how does peritonitis present
abdominal pain, distension, nausea, vomiting, fever
causes of peritonitis
complication of untreated appendicitis. happens when microbes spread through wall of appendix and infect the peritoneum, an appendix abscess perforates and pus enters the peritoneal cavity, appendix becomes gangrenous and perforates, discharging its contents into the peritoneal cavity
effects of peritonitis on the body
peritoneum becomes acutely inflamed, the blood vessels dilate and excess serous fluid is secreted
what is crohns disease
a type of inflammatory bowel disease
how does crohns disease present
abdominal pain, diarrhoea, weight loss
causes of Crohn’s disease
usually between 20-40, smoking, both sexes affected easily
effects of crohns disease on body
chronic patchy inflammation with oedema of the full thickness of the intestinal wall, causing partial obstruction of the lumen. mainly affects terminal ileum and rectum
what is ulcerative colitis
chronic inflammatory disease of the mucosa of the colon and rectum
how does ulcerative colitis present
bloody diarrhoea
what causes ulcerative colitis
usually between 20-40, both sexes affected equally
effects of ulcerative colitis on the body
inflammatory disease that begins in the rectum and spreads proximally to the colon. ulcerates and can become infected
