Exam 3: GI Pathophysiology

Question 1

After a meal, blood pH shifts:

Answer 1

More alkaline d/t shift of H+ into lumen of stomach, HCO3- into blood

Question 2

Once food enters duodenum, blood pH shifts:

Answer 2

Back to normal; HCO3- is dumped into lumen to increased pH

Question 3

Hiatal hernia is caused by:

Answer 3

Stomach moving through opening in diaphragm by esophagus

Question 4

Sequalae of hiatal hernia:

Answer 4

Trapping of food in esophagus and heartburn/regurg

Question 5

Achalasia is:

Answer 5

Loss of inhibitory innervation of LES, leading to food sitting in esophagus instead of moving into stomach

Question 6

Causes of achalasia:

Answer 6

Aperistalsis
Incomplete relaxation of LES
↑ tone of LES

Question 7

Sequlae of achalasia:

Answer 7

Dysphagia
Mucosal inflammation/ulceration
Squamous cell carcinoma (5%)

Question 8

Cause of esophageal varices:

Answer 8

Impaired hepatic portal blood flow –> portal HTN –> blood backup to esophagus

Question 9

% of cirrhosis pts with esophageal varices:

Answer 9

2/3rds

Question 10

Sequelae of esophageal varices:

Answer 10

Rupture & hemorrhage

Hematemesis

Question 11

Mortality rate of ruptured esophageal varices:

Answer 11

20-30% per episode with a 70% recurrence rate

Question 12

Barrett’s esophagus is:

Answer 12

Metaplastic change from esophageal cells to stomach cells

Question 13

Contributing causes to GERD:

Answer 13

Obesity
Hiatal hernia
Vagal nerve abnormalities

Question 14

Cause of Barrett’s esophagus:

Answer 14

Long standing GERD

Question 15

Sequelae of Barrett’s esophagus:

Answer 15

Adenocarcinoma

Question 16

Two types of esophageal cancers:

Answer 16

Squamous cell carcinoma

Adenocarcinoma

Question 17

Conditions predisposing to SCC:

Answer 17

Tobacco use
Alcohol use
Achalasia
Drinking very hot tea??

Question 18

Conditions predisposing to adenocarcinoma:

Answer 18

Barrett’s esophagus/GERD

Question 19

S/s of esophageal CA:

Answer 19

Dysphagia
Obstruction
(Typically late in progression)

Question 20

Chronic gastritis can lead to:

Answer 20

Peptic ulcers

Question 21

Acute gastritis can lead to:

Answer 21

Acute gastric ulceration

Question 22

Normal stomach pH:

Answer 22

1.5

Question 23

Gastric pits are:

Answer 23

Depressions in epithelial lining containing gastric glands

Question 24

Chief cells produce:

Answer 24

Gastric juice enzymes

Question 25

Parietal cells produce:

Answer 25

Stomach acid

Question 26

Chronic gastritis/PUD usually caused by:

Answer 26

H. pylori

Question 27

H. pylori survives in stomach by:

Answer 27

Secreting ammonia as buffer against gastric acid

Question 28

S/s of H. pylori:

Answer 28

Upper abdo discomfort N/V Ulcers

Question 29

Peptic ulcers are:

Answer 29

Chronic lesions anywhere in the GI tract exposed to acid, although 98% are in proximal duodenum/stomach (4:1)

Question 30

Causes of peptic ulcers:

Answer 30

``` H. pylori NSAIDs Smoking Alcohol Corticosteroids Stress ```

Question 31

S/s of peptic ulcers:

Answer 31

Epigastric pain N/V Hemorrhage Perforation NOT cancer

Question 32

Acute gastritis is:

Answer 32

Acute, usually transient, mucosal inflammation

Question 33

Causes of acute gastritis:

Answer 33

``` Just about anything NSAIDs ETOH Smoking Chemo Uremia Sepsis Ischemia, shock, stress Ingestion Trauma to stomach ```

Question 34

S/s of acute gastritis:

Answer 34

Epigastric pain N/V Hematemesis Melena

Question 35

Most common type of stomach cancer:

Answer 35

Gastric carcinoma (> 90%)

Question 36

Causes of intestinal-type adenocarcinoma:

Answer 36

``` Nitrites/nitrates Smoked, pickled, salty food ↓ in fruit/veg consumption Chronic gastritis H. pylori ```

Question 37

Causes of diffuse carcinoma:

Answer 37

Not well understood

Question 38

Four layers of intestine from outermost to innermost:

Answer 38

Serosa Muscularis Submucosa Mucosa

Question 39

If starches are not absorbed or broken down:

Answer 39

Bacteria will eat them, leading to cramps and bloating

Question 40

Non-digested proteins in the bloodstream cause:

Answer 40

Inflammation and the creation of antibodies/immune response

Question 41

Monosaccharide uptake is aggressive due to:

Answer 41

Glucose and galactose being taken in via Na+ cotransporters

Question 42

Most at-risk blood supply in the GI system:

Answer 42

Splenic flexure

Question 43

Developmental problem behind Hirchsprung's:

Answer 43

Aganglionic segment of distal colon lacks Meissner & Auerback plexuses and thus has no peristalsis

Question 44

Sequelae of Hirchsprung's:

Answer 44

Obstruction Enterocolitis Perforation After removal of large segment: chronic diarrhea d/t minimal H2O absorption

Question 45

Tx of Hirchsprung's:

Answer 45

Removal of aganglionic segment

Question 46

Worst case scenario for ischemic bowel disease:

Answer 46

Transmural infarction - 90% mortality rate

Question 47

Five causes of ischemic bowel disease:

Answer 47

``` Arterial thrombosis Arterial embolism Venous thrombosis Non-occlusive ischemia Mechanical obstruction ```

Question 48

Cause of hemorrhoids:

Answer 48

Straining during defecation Pregnancy (caval obstruction backs up to portal-caval anastamoses) Hepatic portal hypertension

Question 49

Secretory diarrhea:

Answer 49

Caused by bacterial infections Ex. cholera Can lose 1L/hr!

Question 50

Cholera causes diarrhea by:

Answer 50

Causing epithelium to lose Cl- into the lumen, which inhibits Na+ uptake and H2O uptake

Question 51

Osmotic diarrhea:

Answer 51

Due to non-digestible agents in the lumen that act as osmotic agents Ex. GoLytely

Question 52

Exudative diarrhea:

Answer 52

Due to destruction of epithelial layer - not enough viable tissue, poor absorption Ex. shigella, salmonella, campylobacter, etc

Question 53

Malabsorption diarrhea:

Answer 53

Ex. lactose intolerance, giardia, lympatic obstruction d/t fat buildup Bacterial feeding on ingested food causes bloating, gas, diarrhea

Question 54

Deranged motility diarrhea:

Answer 54

D/t surgery or hyperthyroidism Usually ↓ motility but can sometimes be ↑

Question 55

Dx'ing CD vs UC:

Answer 55

Colonoscopy - UC will be in the colon with pseudopolyps | X-ray - can show wall thickening

Question 56

Distribution of ulcerative colitis:

Answer 56

In the colon in one continuous section, starting at anus and going backwards

Question 57

Distribution of Crohn's disease:

Answer 57

Anywhere from mouth to anus, usually in intestines Skip lesions Deep fissures, not ulcers

Question 58

Diverticula are:

Answer 58

Pouches protruding out of the bowel

Question 59

Diverticulitis is:

Answer 59

When diverticula get inflamed

Question 60

Sequelae of diverticulitis:

Answer 60

Perforation | Fistula formation

Question 61

S/s of diverticulitis:

Answer 61

LLQ pain | Bleeding

Question 62

Tx of diverticulitis:

Answer 62

Fiber

Question 63

Types of mechanical bowel obstruction:

Answer 63

Herniation Adhesions Intussception Volvulus

Question 64

Types of pseudo-obstructions:

Answer 64

Paralytic ileus Bowel infarction Myopathies/neuropathies

Question 65

Colonic tumor becomes invasive when:

Answer 65

Penetrates the muscularis mucosae and enters submucosal layer

Question 66

S/s of colorectal carcinoma:

Answer 66

Pain Obstruction Changes in bowel habits

Question 67

S/s of left-sided colorectal CA:

Answer 67

Visible blood in stool, LLQ pain

Question 68

S/s of right-sided colorectal CA:

Answer 68

Fatigue Weakness Iron deficiency anemia