GI

Question 1

What makes up the GI tract?

Answer 1

Oral cavity

esophagus

stomach

small intestine

large intesting

Question 2

What does the stomach acid do?

What else happens in the stomach?

Answer 2

Denatures proteins and kills most pathogens

adds or removes water until bolus is isotonic

Question 3

What are the anatomical and motor disorders of the esophagus?

Answer 3

• Hiatal hernia
• achalasia
• esophageal varices

Question 4

What is a hiatal hernia?

Answer 4

• stomach protrudes up into diaphragm
  
  • sliding- food enters stomach from esophagus and gets caught in the pouch above the diaphragm
• symptoms:
  
  • Heart burn
  • regurgitation
  • **can cause barrets esophagus and then cancer
• increases with age

Question 5

Achalasia

Answer 5

• Food gets stuck in your esophagus
  
  • food that sits there then starts to errode the esophagus
• lower esophageal sphinctor doesn’t open properly
  
  • or has increased resting tone
• usually happens more to older people
• symptoms
  
  • dysphagia
  • mucous membrane errosion
  • barrets esophagus –>squamus cell carcinoma

Question 6

What are esophageal varices?

What is the big problem with these?

Answer 6

• Varicose veins in esophagus
• caused by impaired hepatic portal blood flow
  
  • associated with alcoholic cirrhosis (~2/3 of cirrhosis patients)
• big problem is rupture
  
  • hematemesis- vomiting blood
  • 20-30% die on each episode of rupture
  • 70% recurrence rate
  • *often also have coagulopathies related to liver disease

Question 7

What is Mallory-Weiss Syndrome?

Answer 7

severe and prolonged (traumatic) vomiting can cause tears in esophagus

*usually not a huge problem because if they dont have cirrhosis, then they will not have coagulophathies and will stop bleeding.

Question 8

Reflux esophagitis

Answer 8

• When the lower esophageal sphinctor doesnt close properly
  
  • causes heartburn and barret esophagus
• contributing factors
  
  • obesity
  • hiatal hernia
  • vagal nerve abnormalities

Question 9

What is barrett esophagus?

Answer 9

• replacement of normal stratified squamus mucosa with metaplastic columnar epithelium with goblet cells
• Can lead to cancer

Question 10

What are the two esophageal cancers?

Answer 10

• Squamous cell carcinoma- occurs where you have normal esophageal tissue (no barretts)
  
  • caused by tobacco, alcohol, achalasia, very hot tea (>65 C)
• Adenocarcinoma
  
  • caused by barrett esophagus
  • symptoms: dysphagia and obstruction

Question 11

What is Zenker’s Diverticulum?

Answer 11

• part of food bolus gets trapped in the pouch
• more common in pts over 60
• symptoms
  
  • dysphagia
  • regurgitation
  • cough
  • halitosis (food rots in the pouch, causing bad breath)
  • usually painless
  • may cause infection and perforation (rare)

Question 12

What is Chronic gastritis?

Answer 12

• Usually caused by H. pylori
  
  • will start to errode stomach lining
  • usually asymptomatic
    
    • maybe stomach discomfort, N/V
• Can continue to becme peptic ulceration

Question 13

What are peptic ulcers?

Answer 13

• Chronic lesions that can be anywhere in GI tract but 98% are in proximal duodenum and stomach (4:1)
  
  • H. pylori is involved in 70-90% of duodenal ulcer and 70% of gastric ulcers
• Only 10-20% of ppl w/ H. Pylori get ulcers

Question 14

What aggravates peptic ulcers?

Answer 14

• NSAIDS
• smoking
• alcohol
• corticosteroids
• high stress personality??
• gastrinoma (zollinger-ellison syndrome)

Question 15

What problems do peptic ulcers cause?

Answer 15

• epigastric pain
• nausea and vomiting
• hemorrhage and perforation
• generally do NOT progress to cancer
• ** usually just impair quality of life rather than shorten it
  
  • 15,000 deaths/year attributed to complications of peptic ulcers

Question 16

Why do NSAIDS exacerbate ulcers?

Answer 16

decrease prostaglandins which decreases mucous layer

(prostaglandins stimulate mucousal production)

Question 17

What is a gastrinoma?

Answer 17

a hormone producing tumor

Question 18

What is acute (stress) gastritis?

Answer 18

• Completely different from chronic and does not progress to chronic
• Causes:
  
  • heavy NSAID use
  • excessive alcohol
  • heavy smoking
  • chemo
  • uremia
  • systemic infections
  • severe stress (trauma, burn, surgery)
  • ischemia and shock
  • ingestion of caustic agents (acids or bases)
  • mechanical trauma (nasogastric intubation)
• Problems:
  
  • epigastric pain with N/V
  • Hematemesis and/or melena (bloody stool)

Question 19

How did we cure stomach cancer?

Answer 19

refrigeration

*before refrigerators ppl ate all smoked or pickled foods for winter

Question 20

What are the two types of stomach cancers?

Answer 20

• Intestinal-type adenocarcinoma (the type of cancer cured with refrigeration)
  
  • caused by nitrites, preservatives
  • smoked food
  • excessive salt
  • decreased fruit and veg consumption
  • chronic gastritis
  • H. pylori
• Diffuse carcinoma
  
  • risk factors poorly understood; we have not cured this type

Question 21

What is the third leading cause of cancer death worldwide?

Answer 21

gastric carcinoma

1st- lung

2nd- liver

Question 22

How are carbohydrates, proteins, and fats digested?

(chart)

Answer 22

Question 23

What part of GI tract is most at risk for ischemia if there is a shortage (shock)?

Answer 23

splenic flexure

Question 24

What is Hirschsprung disease?

Answer 24

• Neural crest cells don’t make it all the way to the end of the colon (caudal migration) during fetal formation leaving an aganglionic segment
• distal colon lacks both meissner and auebach myenteric plexus
  
  • no peristalsis past where there are no nerves
• Problems
  
  • obstruction
  • enterocolitis
  • perforation
• Fixed by removing the aganglionic segment

Question 25

What is ischemic bowel disease?

Answer 25

* acute occlusion or hypoperfusion can result in infarction * Mucosal- not a big deal, make for mucous * mural- More severe, but not the worst * Transmural infarction- Goes all the way through the intestinal wall * becomes friable- easy to perforate, like trying to suture a wet tissue; whatever was in the lumen is now in the abdomen *

Question 26

What are the causes of ischemic bowel?

Answer 26

* arterial thrombosis * arterial embolism * venous thrombosis * nonocclusive ischemia * cardiac failure, shock, dehydration, vasoconstrictive drugs * mechanical obstruction * volvulus, stricture, herniation

Question 27

What is the mortality of transmural bowal infarction?

Answer 27

90%! They were probably already sick when the bowel infarcted

Question 28

What causes hemorrhoids?

Answer 28

1. straining during defecation- strain causes increased venous pressure 2. pregnancy- later in pregnancy 3. portal hypertension- similar to esophageal varices

Question 29

What causes cholera?

Answer 29

* Secretory (cholera)- produces toxin that causes chloride to leak into lumen, prevenitn Na from being reabsorbed. Water goes to lumen. Difficult to keep this person hydrated

Question 30

What are osmotic causes of diarrh

Answer 30

* Gut lavage- goal to clean out the GI tract * too much golytely causes dehydration with some kind of electrolyte imbalance

Question 31

What are all the major causes of diarrhea?

Answer 31

* Secretory- cholera * osmotic- golytely * exudative- IBD (crohn's and UC) * Infectious- shigella, salmonella, campylobacter, C.diff * C.diff can take over after antibiotics * Malabsorption- defective absorption (lactose, gluten) * Deranged motility- surgery, hyperthyroidism

Question 32

What is irritable bowel syndrom?

Answer 32

* chronic "crummy tummy" * IBD is WAY worse than IBS

Question 33

Where does UC start?

Answer 33

* Ulcers in colon * Starts at the anus and goes back from there. Amount of colon involved depends on extent of disease * Pseudopolys- part of tissue wall stays forward as all the neighboring tissue becomes ulerated and errodes back

Question 34

What part of the bowel does crohn's disease affect?

Answer 34

* some parts are affected, others are normal (skip lesions) * causes deep fissures that go through mucosal layer and can even cause fistulas from lumen of intestine to abdomen * structures form, making intestine walls thicker

Question 35

What are the different smptoms of Crohn's vers UC? (chart)

Answer 35

Question 36

What are the common symptoms between Crohn's and UC?

Answer 36

Diarrhea loss of appetite painful bowel movement frequent bowel movement weight loss fatigue

Question 37

Whats this?

Answer 37

* The hook worm!! A possible cure for crohn's?!? * causes hemorrhagic anemia with no bleeding * the hook worm "turns off" the pts immune system so that it can survive

Question 38

What is the lifecycle of the hookworm?

Answer 38

* lives in intestines, sucks blood, lays eggs * eggs come out of body in feces, get into soil and hatch * larva bore into the ground and then bore into a person's foot when they walk over that ground * the larva make their way into person's lungs, get coughed up in sputum and then swallowed into GI tract to start cycle again

Question 39

What is the other high yuck factor medical treatment discussed in class?

Answer 39

* Fly maggots * eat dead flesh but not live tissue * can be sprinkled on a necrotic wound and a few days later it is nice and clean * alternative to amputation

Question 40

What is diverticulosis/diverticulitis? What causes it? Where does it usually occur? symptoms? prevention?

Answer 40

* Diverticulosis- pouches that protrude out of the bowel * occur in about 50% of ppl over 50 years old and increase with age * diverticulitis- inflammation of the pouches * occurs mostly in descending colon where the stool is very thick and difficult to move along * Left lower quadrant pain * prevent by eating more fiber, avoid food with small seeds

Question 41

What are the different types of mechanical bowel obstructions?

Answer 41

* hernias- intestine seeps through inguinal canal; bolus can't get through easily and neither can blood * adhesions- scar tissue binds bowel together so it cant move as well * intussusception * vulvulus- twisting

Question 42

What are some pseudo obstructions?

Answer 42

* paralytic ileus- bowel doesnt work so content just builds up * bowel infarction- muscle damage prevents peristalsis * myopathies and neuropathies (herschsprung)

Question 43

Which intestine has the greater occurance of cancer?

Answer 43

large intestine

Question 44

Definitions: polyp pedunculated sessile

Answer 44

* **polyp**- a tumorous mass protruding into the lumen * **pedunculated**- having a stalk * **sessile**- not having a stalk

Question 45

adenoma

Answer 45

neoplastic polyp arising from epithelial proliferation and dysplasia

Question 46

adenocarcinoma

Answer 46

* cancer arrising from adenomatous polyps (98% of colorectal cancers)

Question 47

Carcinoid tumor

Answer 47

tumors of neuroendocrine cells, found in stomach, intestines, and lung

Question 48

What are the differences between a cancer on the right side vs left side?

Answer 48

* **right-** fatigue, weakness * iron deficient anemia * blood on guiac, but wont see it in stool * **Left**- no anemia because pt will see blood in stool and will get checked