lOMoARcPSD| 63525276
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NR507 – Advanced Pathophysiology:
Final Exam Study Guide (In‑Depth)
Week 5 – Gastrointestinal & Neurobiological
Pathologies
Gastroesophageal Reflux Disease (GERD)
Pathophysiology
● Transient lower esophageal sphincter (LES) relaxations and/or hypotensive LES →
reflux of gastric contents → esophagitis (acid + pepsin + bile salts).
● Risk amplifiers: hiatal hernia, delayed gastric emptying, obesity (↑ intra‑abdominal
pressure), pregnancy, ETOH, nicotine, chocolate, caffeine, certain meds (CCBs,
nitrates, anticholinergics, theophylline).
Clinical
● Heartburn (post‑prandial, supine), regurgitation, sour taste, chronic cough/hoarseness,
dysphagia (stricture). Alarm: dysphagia, odynophagia, weight loss, GI bleed, anemia.
Complications
● Erosive esophagitis → stricture (fibrosis/narrowing).
● Barrett’s esophagus (intestinal metaplasia) → ↑ risk adenocarcinoma.
Diagnosis
● Typical symptoms → empiric PPI trial.
● Alarm features or refractory → EGD ± biopsy. Ambulatory pH impedance if unclear.
, lOMoARcPSD| 63525276
Management
Lifestyle: weight loss (highest impact), elevate HOB, avoid late meals, triggers.
● Pharmacologic: PPIs > H2RAs; add alginate antacids PRN.
● Refractory/complicated: EGD; surgical options (Nissen fundoplication) esp. with large
hiatal hernia.
Exam Pearls
● Long‑standing GERD → progressive solid food dysphagia = peptic stricture.
● Chronic GERD + intestinal metaplasia on biopsy = Barrett’s.
Hiatal Hernia
Types: Sliding (95%) vs Paraesophageal.
Tx: Treat GERD; surgery for paraesophageal (risk of strangulation) or refractory symptoms.
Appendicitis
Pathophysiology: Lumen obstruction (fecalith/lymphoid hyperplasia) → venous
congestion → ischemia → bacterial overgrowth → transmural inflammation → perforation.
Clinical: Periumbilical → RLQ pain (McBurney), anorexia, N/V, low‑grade fever;
psoas/obturator/Rovsing signs.
Labs/Imaging: Leukocytosis with left shift; CRP ↑. Adult diagnosis: CT abd/pelvis with
contrast (US in children/pregnancy).
Risks in adults: perforation, abscess, ileus; peri‑op: wound infection, adhesions.
Peptic Ulcer Disease (PUD)
Mechanisms
● H. pylori (↑ gastrin, ↓ somatostatin; cytotoxins; mucosal inflammation).
● NSAIDs (↓ prostaglandins → ↓ mucus/bicarbonate, ↓ mucosal blood flow).
● Hypersecretory states (Zollinger–Ellison).
, lOMoARcPSD| 63525276
●
Risk Factors: H. pylori, NSAIDs, steroids + NSAIDs, smoking, severe illness (stress ulcers),
prior PUD, chronic ETOH.
Gastric vs Duodenal
● Gastric: Pain worse with meals → weight loss; older pts; antrum < body; H. pylori
60–70%.
● Duodenal: Pain relieved by meals; nocturnal pain; H. pylori ~90%; younger.
Complications: Bleeding (posterior duodenal → gastroduodenal artery), perforation (free air
under diaphragm), gastric outlet obstruction.
Diagnosis: EGD with biopsy for gastric ulcers; noninvasive H. pylori tests (urea breath,
stool antigen) off PPI >2 wks.
Treatment:
● H. pylori: Bismuth quadruple or concomitant therapy (institutional protocol);
confirm eradication.
● NSAID ulcers: stop NSAID, PPI 8–12 wks; consider COX‑2 + PPI if must continue.
Exam Pearls: Pain pattern table; posterior duodenal bleed; perforation → shoulder pain +
rigid abdomen.
Inflammatory Bowel Disease (IBD)
Ulcerative Colitis (UC)
● Patho: Continuous mucosal inflammation starting at rectum → limited to colon.
Th2‑like cytokine milieu.
● Clinical: Bloody diarrhea, urgency/tenesmus, LLQ cramps. Extraintestinal: PSC,
erythema nodosum, uveitis.
● Risks: Toxic megacolon; colorectal cancer (risk correlates with duration/extent).
● Tx: 5‑ASA (mild), corticosteroids (flares), immunomodulators/biologics for
moderate‑severe; surgery is curative (colectomy).
●
NR507 – Advanced Pathophysiology:
Final Exam Study Guide (In‑Depth)
Week 5 – Gastrointestinal & Neurobiological
Pathologies
Gastroesophageal Reflux Disease (GERD)
Pathophysiology
● Transient lower esophageal sphincter (LES) relaxations and/or hypotensive LES →
reflux of gastric contents → esophagitis (acid + pepsin + bile salts).
● Risk amplifiers: hiatal hernia, delayed gastric emptying, obesity (↑ intra‑abdominal
pressure), pregnancy, ETOH, nicotine, chocolate, caffeine, certain meds (CCBs,
nitrates, anticholinergics, theophylline).
Clinical
● Heartburn (post‑prandial, supine), regurgitation, sour taste, chronic cough/hoarseness,
dysphagia (stricture). Alarm: dysphagia, odynophagia, weight loss, GI bleed, anemia.
Complications
● Erosive esophagitis → stricture (fibrosis/narrowing).
● Barrett’s esophagus (intestinal metaplasia) → ↑ risk adenocarcinoma.
Diagnosis
● Typical symptoms → empiric PPI trial.
● Alarm features or refractory → EGD ± biopsy. Ambulatory pH impedance if unclear.
, lOMoARcPSD| 63525276
Management
Lifestyle: weight loss (highest impact), elevate HOB, avoid late meals, triggers.
● Pharmacologic: PPIs > H2RAs; add alginate antacids PRN.
● Refractory/complicated: EGD; surgical options (Nissen fundoplication) esp. with large
hiatal hernia.
Exam Pearls
● Long‑standing GERD → progressive solid food dysphagia = peptic stricture.
● Chronic GERD + intestinal metaplasia on biopsy = Barrett’s.
Hiatal Hernia
Types: Sliding (95%) vs Paraesophageal.
Tx: Treat GERD; surgery for paraesophageal (risk of strangulation) or refractory symptoms.
Appendicitis
Pathophysiology: Lumen obstruction (fecalith/lymphoid hyperplasia) → venous
congestion → ischemia → bacterial overgrowth → transmural inflammation → perforation.
Clinical: Periumbilical → RLQ pain (McBurney), anorexia, N/V, low‑grade fever;
psoas/obturator/Rovsing signs.
Labs/Imaging: Leukocytosis with left shift; CRP ↑. Adult diagnosis: CT abd/pelvis with
contrast (US in children/pregnancy).
Risks in adults: perforation, abscess, ileus; peri‑op: wound infection, adhesions.
Peptic Ulcer Disease (PUD)
Mechanisms
● H. pylori (↑ gastrin, ↓ somatostatin; cytotoxins; mucosal inflammation).
● NSAIDs (↓ prostaglandins → ↓ mucus/bicarbonate, ↓ mucosal blood flow).
● Hypersecretory states (Zollinger–Ellison).
, lOMoARcPSD| 63525276
●
Risk Factors: H. pylori, NSAIDs, steroids + NSAIDs, smoking, severe illness (stress ulcers),
prior PUD, chronic ETOH.
Gastric vs Duodenal
● Gastric: Pain worse with meals → weight loss; older pts; antrum < body; H. pylori
60–70%.
● Duodenal: Pain relieved by meals; nocturnal pain; H. pylori ~90%; younger.
Complications: Bleeding (posterior duodenal → gastroduodenal artery), perforation (free air
under diaphragm), gastric outlet obstruction.
Diagnosis: EGD with biopsy for gastric ulcers; noninvasive H. pylori tests (urea breath,
stool antigen) off PPI >2 wks.
Treatment:
● H. pylori: Bismuth quadruple or concomitant therapy (institutional protocol);
confirm eradication.
● NSAID ulcers: stop NSAID, PPI 8–12 wks; consider COX‑2 + PPI if must continue.
Exam Pearls: Pain pattern table; posterior duodenal bleed; perforation → shoulder pain +
rigid abdomen.
Inflammatory Bowel Disease (IBD)
Ulcerative Colitis (UC)
● Patho: Continuous mucosal inflammation starting at rectum → limited to colon.
Th2‑like cytokine milieu.
● Clinical: Bloody diarrhea, urgency/tenesmus, LLQ cramps. Extraintestinal: PSC,
erythema nodosum, uveitis.
● Risks: Toxic megacolon; colorectal cancer (risk correlates with duration/extent).
● Tx: 5‑ASA (mild), corticosteroids (flares), immunomodulators/biologics for
moderate‑severe; surgery is curative (colectomy).
