GI Flashcards
What is the role of serotonin in the gut?
stimulates gut motility
What is the primary cause of GERD?
LES malfunction
What tissue is damaged from exposure to stomach acid in GERD?
squamous cell lining of the lower esophagus
What causes Esophagitis?
GERD (most common cause)
Allergies
Meds (NSAIDS and Antibiotics)
Smoking, excessive ETOH
Obesity
What cell changes occur in Barretts Esophagus?
squamous cells turn into metaplasic columnar epithelium
Barretts esophagus is a precursor to…
adenocarcinoma of the esophagus
What are the complications of GERD?
Esophagitis
Barrett’s Esophagus
Esophageal CA
Strictures
What is Odynophagia
painful swallowing
Why is Barrett’s Esophagus often diagnosed late?
early symptoms are subtle; leads to poor prognosis
What happens in the GI tract when cells are damaged?
inflammation, ulceration
Major risk factors for esophageal CA?
Smoking
ETOH
Obesity
Barretts Esophagus/GERD
Most common cause of peptic ulcer disease
H. Pylori infection
How do NSAIDS damage the mucosa in gastritis?
inhibits production of prostaglandins which maintain mucus production and protective barrier against stomach acid
How does autoimmune gastritis affect the hematological system?
Causes B12 deficiency, leading to pernicious anemia
How does autoimmune gastritis cause B12 deficiency?
destroys parietal cells in stomach lining, which are responsible for producing intrinsic factor
Major risk factors of gastric CA…
Chronic gastritis
H pylori
Epstein Barr Virus
poor diet
pernicious anemia
What sub-type of gastritis is H pylori associated with?
Type B
Epigastric pain with duodenal ulcer is typically ______ by eating
relieved
Epigastric pain with gastric ulcer is typically _____ with eating
increased or worsened
Basic Pathophysiology of Chron’s disease
immune system mistakenly attacks the GI tract lining and causes chronic inflammation
What cells from the innate immune system are involved in Chrons
Dendritic cells and Macrophages
-antigen presenting cells constantly sense bacterial antigens d/t impaired mucosal barriers=constant T1H cell activation
What cells from the adaptive immune system are involved in Chrons?
-T1H produce interferon gamma= activates macrophages and continues inflammation loop
T17 releases cytokines that sustain/escalate inflammation
What happens with cytokine storm in Chrons?
Excessive release of cytokines = tissue damage, which worsens symptoms
Transmural inflammation in Chrons leads to what?
thickening/scarring of the intestinal wall as it tries to heal
-causes fibrosis/strictures=obstructions
What is the hallmark of Chrons?
Granulomas form and cause skip lesions-Cobblestone appearance
What is dybiosis?
an imbalance in the gut microbiota that contributes to immune system misfire in the gut
Where in the GI tract is Ulcerative Colitis (UC) found?
large intestine and rectum
Where in the GI tract is Chrons found
Can be found anywhere in the GI tract but commonly in the ileum and beginning of the lrg intestine
What are the lab values for Chrons
-Elevated CRP (higher than in UC)
-Elevated fecal calprotectin (indicate
inflammation)
-Anemia, Leukocytosis,
Thrombocytosis
Patho of UC
-genetic predisposition-
disruption of the epithelial barrier fxn of the colon (starts in rectum) = abnormal immune response causing inflammation and ulceration in the mucosal lining
Epithelial barrier dysfunction leads to…
decreased goblet cell production which = decrease in protective mucus which leaves lining vulnerable to bacteria and toxins
-Leaky gut d/t tight junctions btween cells weaken and allow bad things to pass through
What does chronic ulceration of the lrg intestine do in the long run?
exposes deeper tissue layers over time, which attracts more immune cells that cause further damage (neutrophils and lymphocytes)
What is the hallmark of UC?
Crypt abscess formation (clusters of neutrophils w/in colonic crypts)
-indicates severe inflammation and bacterial invasion
How does dysbiosis contribute to UC?
Short Chain Fatty Acids(SCFA’s) are produced by beneficial bacteria; loss in this=decreased SCFA production =impaired mucosal barrier
Lab values in UC
-Elevated CRP (lower than in Chrons)
-Elevated fecal calprotectin (indicate
inflammation)
-Anemia, Leukocytosis,
Thrombocytosis
What is IBS?
chronic functional GI disorder- altered bowel habits with an identifiable cause
How does IBS differ from IBD?
IBS does not cause inflammation or cause permanent harm to the GI tract
IBS DOES cause inflammation and damage to the
Characteristics of IBS
abd pain accompanied by change in bowel habits (diarrhea, constipation, or both), bloating
Triggers of IBS
Changes in routine
Stress
certain foods
