Gastrointestinal Pathology Flashcards
What is another name for Dental Caries?
Cavities
What bacterium is responsible for the formation of dental plaque?
Streptococcus mutans
What causes dental caries to form?
Oral bacteria convert sugar into acids, which destroy the enamel and dentin of teeth
What is gingivitis? Cause?
- Inflammation of the oral mucosa immediately around the teeth
- Caused by oral bacteria forming biofilm (plaque) beneath the gum line
What are the symptoms of gingivitis?
- Gingival erythema and edema
- Bleeding
- Changes in contour
- Loss of soft tissue around the teeth
- Periodontitis (eventual loss of teeth)
About how much saliva do you produce per day?
~ 1.2 liters
What are the components of saliva? (4)
- Proteins (enzymes)
- Glycoproteins (mucins and conjugated antibodies)
- Ions/water (bicarb for buffering)
- IgA
Xerostomia is another name for?
Dry mouth
What medication is used to stimulate salivary glands in patients with Xerostomia?
Pilocarpine
What are some complications of xerostomia? (4)
- Increased rates of dental caries
- Increased risk of candidiasis (oral thrush)
- Dysphagia (difficulty swallowing)
- Dysarthria (difficulty speaking)
What is Atresia?
- Lack or limitation of a space or lumen
- Usually developmental
- Results in mechanical obstruction of the space or tube
What is a Fistula?
- Abnormal opening between tubes
What are esophageal varices?
- Distension of veins around the esophagus
- Rupture can result in fatal hemorrhage
What is reflux esophagitis? What is it known as clinically?
- Gastroesophageal Reflux Disease (GERD)
- Movement of stomach (or pancreatic) contents into the esophagus
- Damages the esophageal mucosa
What nerve is responsible for controlling the lower esophageal sphincter (LES)?
Vagus nerve
What neurotransmitters can act on the LES?
- Nitric oxide (NO)
- Vasoactive intestinal peptide (VIP)
What foods can contribute to GERD?
**Mint Mochaccino**
- Peppermint
- Coffee
- Chocolate
What is a hiatal hernia?
- Herniation of the stomach through the opening of the diaphragm for the esophagus
What is Barrett’s esophagus?
- Metaplasia of the esophagus due to stomach acid damage
- Esophageal epithelium changes from stratified squamous to columnar with goblet cells
- Precancerous
What class of drugs are associated with gastric ulcers?
- NSAIDs
- Aspirin
What is duodenal reflux?
- Duodenal contents re-enter the stomach through the pyloric sphincter; brings bile into the stomach
- Food retention increases, gastric acid is produced
- Can lead to gastric ulcers
What are the functions of prostaglandins in the stomach? (3)
- Increase mucosal blood flow
- Promote bicarbonate and mucus secretion
- Stimulate mucosal repair and renewal
Why can NSAIDs cause gastritis and ulcers?
- Inhibits prostaglandin production
What bacterium is known to cause gastric ulcers?
Helicobacter pylori
What are the effects of an H. pylori infection? (3)
- Increased acid production through gastrin and somatostatin release
- Mucosal damage secondary to immune response
- Reduced bicarbonate secretion by inhibiting urease
True or false. Ulcers can be related to stress?
True. Including trauma, surgery, or serious medical disease
What is pernicious anemia?
- Failure of DNA synthesis affecting hematopoiesis
- Vitamin B12 deficiency, thymidine synthesis impaired
True or false. Gastric ulcers are more common than duodenal ulcers?
False. Duodenal are more common; still a result of H. pylori
What is a volvulus?
- Intestinal obstruction
- Caused by twisting of the bowl
What is intussuception?
- Segment of the intestines slides into the next segment
- Usually happens during peristalsis
How is intussusception treated? (2)
- Contrast or air enemas
- Surgery
What are some common causes of malabsorption? (4)
- Celiac disease
- Pancreatitis
- Cystic fibrosis
- Inflammatory bowel disease
The most common clinical symptom of malabsorption is _____
chronic diarrhea
True or false. Celiac disease is autoimmune
False. It’s not autoimmune
What about celiac disease causes malabsorption?
- Damage from immune response to gluten
- Loss of brush borders and villi
What is another name for infectious enterocolitis?
Acute IBD
How does cholera cause watery stool and diarrhea?
- Vibrio cholera produce toxin
- Increased chloride secretion, water follows, leads to watery stool and diarrhea
What organism is responsible for causing cholera?
Vibrio cholera
Explain the pathology of cholera
- bacterium produce an A-B toxin
- Increases chloride secretion, which in turn causes water excretion
What organism is responsible for causing Traveler’s diarrhea? How is it acquired?
- Campylobacter jejuni
- Ingestion of undercooked chicken, unpasteurized milk, or contaminated water
What diseases do Salmonella enteritidis and Salmonella enterica cause?
- S. enteritidis: nontyphoid fever
- S. enterica: typhoid fever
What type of E. coli:
- Cause traveler’s diarrhea
- Produce heat-labile and heat-stable toxins
Enterotoxigenic E. coli (ETEC)
What type of E. coli:
- Associated with contaminated beef
- Toxins cause dysentery-like disease
Enterohemorrhagic E. coli (EHEC)
What type of E. coli:
- Resistant to acid
- Proliferate intracellularly in M cells overlying Peyer patches
- Similar to shigella
Enteroinvasive E. coli (EIEC)
What organism causes Typhoid fever? Where does it colonize?
- Salmonella enterica
- Peyer patches in the ileum
What organism causes Pseudomembranous colitis?
Clostridium difficile
What is the effect of C. difficile toxin on cells? (3)
- Binds to small GTPases (e.g Rho)
- Disrupts epithelial cytoskeleton (tight junctions)
- Induces cytokine release and apoptosis
What form of chronic ICD results in discontinuous ulcerations and involves the entire thickness of the intestinal wall?
Crohn’s disease
Describe the initial clinical presentation of Crohn’s disease?
- Mild diarrhea
- Fever
- Abdominal pain
What form of chronic ICD results in continuous ulceration limited to just the mucosa of the colon?
Ulcerative colitis
