GI 1 Flashcards
Intrinsic factor is critical for the absorption of what?
vitamin B12
Lack of intrinsic factor leads to what disease?
pernicious anemia
Intrinsic factor is produced by what cells of the stomach?
parietal cells
What does the gastric mucosa protect from?
from auto-digestion from stomach acid
Five properties of the gastric mucosa that protects against stomach acid?
Secretion (3) 1. mucous 2. bicarbonate 3. prostaglandins Physical (2) 4. epithelial barrier 5. mucosal blood flow to remove acid
What is produced that leads to immune gastritis?
Antibodies against parietal cells
Autoimmune gastritis particularly affects what area of stomach?
body
Autoimmune gastritis most common in what age group, atrophy occurs over what timeframe?
Elderly, 2-3 decades of atrophy
Autoimmune gastritis leads to what other diseases? (2)
Pernicious anemia
Megaloblastic, macrocytic anemia
Intestinal metaplasia can result from what condition of the stomach?
Chronic gastritis
Intestinal metaplasma is characterized by what epithelial changes? Where are these cells usually found?
Gastric epithelium replaced by goblet cells and mucous cells.
Goblet cells - small intestine
Mucous cells - pyloric antrum
What is the cause of peptic ulcers?
imbalance between gastroduodenal mucosal defense mechanisms and damaging gastric acid & pepsin
Three places peptic ulcers are found
- esophagus
- stomach
- proximal duodenum
What is the size and shape of a peptic ulcer?
1 to 7 cm
sharply defined
nonelevated margins
smooth base
What is the histological makeup of the peptic ulcer?
FIbrous scar with granulation tissue, inflammation, and necrotic slough that extends into the muscularis propria
What are most gastric malignancies?
adenocarcinoma
Gastric adenocarcinoma associated with infection with what?
H. pylori
Gastric adenocarcinoma associated with what surgery?
Higher risk with partial gastrectomy
Gastric adenocarcinoma have what risk associated with peptic ulcers?
NO direct risk
Gastric carcinoma predilection for what age/gender?
2 to 1 male
mean age 55
Gastric carcinoma more common in what geographical locations (4) ? Why? (2)
Japan, South America, Chile, Eastern Europe
Environment and dietary factors
Are gastric carcinomas increasing or decreasing in the US?
decreasing
What is the most common site of gastric carcinoma?
Rare in what area?
Distal stomach along lesser curvature of the antrum or prepyloric region
Rare in fundus.
What area in the stomach has increasing incidence of gastric carcinoma, due to what?
Cardia, secondary to GERD
What is the diffuse infiltrative type of gastric carcinoma?
Sheets of discohesive cells with vacuoles of mucin displacing nuclei to one side (signet-ring cell)
Creates “linitis plastica” or leather bottle stomach (shrinkage)
What is the Virchow node? Role in gastric carcinoma spread?
The supraclavicular node, lymphatic spread of gastric carcinoma
What is a form of hematogenous spread of gastric carcinoma bilaterally to ovaries?
Krukerberg tumor
Prognosis of gastric carcinoma?
poor, 28% five-year survival rate
Two main growth patterns of gastric carcinoma?
intestinal and diffuse infiltrative
Most common bacterial enteric pathogen & one that causes infective enterocolitis?
Campylobacter jejuni
Pseudomembranous colitis caused by what pathogen
Clostridium difficile
Tissue effects of pseudomembranous colitis?
Enterotoxin causes superficial, gray mucosal exudate, fibrinous necrosis and loosely adherent mucosal debris (pseudomembrane)
Pseudomembranous colitis symptoms?
Fever, toxicity, abdominal pain and diarrhea
Pseudomembranous colitis main predisposing factors?
broad-spectrum antibiotics therapy
GI surgery
GI ischemia
GI burn
Malabsorption syndrome diagnosis criteria (4)
One or more is missing:
- Intraluminal digestion
- Terminal digestion
- Transepithelial transport
- Lymphatic transport
Most common cause of malabsorption syndrome in western hemisphere?
celiac disease
Celiac disease is what?
Atrophy of small intestine villi
Celiac disease etiology - genetic?
Familial linkage with HLA-DQ2, HLA-DQ8
Celial disease etiology - immune?
Immune response to gliadin, a glycoprotein component of gluten; serum antibodies also observed
Celial disease - 3 diagnosing signs
Biopsy of small intestine mucosa
Loss of villous architecture and crypts
Flattened, mosaic pattern
Crohn’s disease is most common in what site? Can occur where?
terminal ileum, may involve any part of GI tract
What lesion pattern is seen in Crohn’s diseaes?
discontinuous pattern/skip lesions
What are the signs of established Crohn’s disease? (4)
Cobblestone pattern and fissured ulcers
Stricture formation
Regional nodes enlarged
“Skip” lesions with areas of normal bowel
Histopathology of Crohn’s disease?
Transmural inflammation with submucosal edema
Ulcers that extend deep into the bowel and form fissures
Fibrous scarring
Noncaseating granulomas
Complications of Crohn’s disease (8)
(SPADE BB) Stricture formation Perforation of bowel Adhesions to other loops of bowel, bladder, abdominal wall Deep ulcers --> fistulae and sinuses Eye, skin, joint, liver complications Bowel cancer Bleeding from ulcers
