GI

Question 0

What is achalasia? What are the problems?

Answer 0

Loss of intrinsic inhibitory innervation of lower esophageal sphincter (LES) causing aperistalsis, incomplete relaxation of LES, and increased resting tone of LES.
The pt feels like they took a huge bite of food, swallowed too much, gets kind of stuck, painful, and relief when the food passes
Problems: dysphagia, mucosal inflammation and ulceration, and squamous cell carcinoma

Question 1

Hiatal hernia symptoms

Answer 1

Heartburn and regurgitation due to pressure on the lower esophagus

Question 2

GERD contributing causes and problems?

Answer 2

Causes: obesity, hiatal hernia, vagal nerve abnormalities
Problems: heartburn, Barrett esophagus (long-standing GERD, replacing normal stratified squamous mucosa with metaplastic columnar epithelium with goblet cells) -> Adenocarcinoma

Question 3

Esophageal cancer: squamous cell carcinoma vs. adenocarcinoma

Answer 3

Squamous cell carcinoma: cancer of normal esophageal tissue caused by smoking, alcohol, achalasia, or very hot tea (China)
Adenocarcinoma (more common in US) is cancer of the metaplastic tissue (bottom of esophagus) caused by Barrett esophagus
Symptoms: dysphagia and obstruction, typically occur late in cancer progression

Question 4

Parietal cells secrete ____ to the stomach and ____ to the blood.

Answer 4

HCl to the stomach and HCO3 to the blood

Question 5

Chronic gastritis is usually caused by what and causes what problems? What’s a good blood test to diagnose?

Answer 5

Caused by H Pylori
Problems: Gastric Ulcers! N/V, pain
H. Pylori secretes ammonia to buffer the stomach acid, so the best test for this is an ammonia level! Most people with H. Pylori DON’T get ulcers, so it doesn’t make sense to go after that with treatment/tests.

Question 6

What aggravates peptic ulcers? What are the problems?

Answer 6

Aggravating causes: NSAIDs, smoking, alcohol, corticosteroids, high stress personality
Problems: epigastric pain, N/V, hemorrhage, perforation
Impairs quality of life without shortening life (doesn’t lead to cancer)

Question 7

Where are peptic ulcers?

Answer 7

98% in proximal duodenum and stomach (4:1)

Question 8

Chronic vs. Acute gastritis?

Answer 8

Chronic leads to peptic ulcers that form scar tissue, fibrosis, not reversible
Acute leads to stress/gastric ulcers, if the problem is fixed, the mucosa can recover completely

Question 9

Acute gastritis causes and problems?

Answer 9

Causes: NSAIDs, alcohol, smoking, cancer chemotherapy, uremia, systemic infection, severe stress (trauma, burns), ischemia, shock, ingestion of acids/bases, mechanical trauma (NG intubation)
Problems: epigastric pain with N/V, hematemesis, melena

Question 10

Gastric/stress ulcer causes?

Answer 10

Focal, acute gastric mucosal defects resulting from severe stress
Causes: trauma, burns, gastric irritants (NSAIDS), head bleed

Question 11

Gastric carcinoma causes? (2nd leading cancer death to lung cancer)

Answer 11

Intestinal-type adenocarcinoma from nitrates (preservative for meat), smoked food, pickled food, salt, chronic gastritis, H pylori, decreased by fruit and vegetables
Diffuse carcinoma causes are poorly understood, but doesn’t include H pylori

Question 12

Where do disaccharides break down to monosaccharides?

Answer 12

Brush-border membrane 
Sucrose = fructose + glucose
Maltose = glucose + glucose
Lactose = glucose + galactose
Only monosaccharides go through to the capillaries

Question 13

What part of the GI tract is most at risk of not getting perfusion when the patient is hypovolemic?

Answer 13

Splenic flexure (between transverse colon and descending colon)

Question 14

What is hirschsprung (congenital megacolon)? What are the 3 problems?

Answer 14

Caudal migration of neural crest cells fail to reach the anus, leaving an ganglionic segment of the distal colon lacking Meissner and Auerbach myenteric plexuses, peristalsis can’t take place at the distal colon.
Problems: obstruction, enterocolitis, and perforation

Question 15

Progression of ischemic bowel disease?

Answer 15

Mucosal infarction (heals in 2 weeks)
Mural infarction (one side of muscle of GI wall)
Transmural infarction (whole muscle of GI wall)

Question 16

What are causes of ischemic bowel disease? Note: mortality is 90%!

Answer 16

Arterial thrombosis/embolism
Venous thrombosis
Nonocclusive ischemia (cardiac failure, shock, dehydration, vasoconstrictive drugs)
Mechanical obstruction (volvulus, stricture, herniation)

Question 17

What are hemorrhoids and what are the top causes for hemorrhoids?

Answer 17

Persistently elevated venous pressure in the hemorrhoidal plexus causing vatical dilations
Caused by straining (men), pregnancy (women), and hepatic portal hypertension

Question 18

What is secretory diarrhea? What’s an example?

Answer 18

Vibrio cholerae (cholera)- spreads in infected water sources
Bacteria that causes mucosal epithelial cells to lose Cl, then we don't take up Na, then we don't take up water, then we dump water into the intestine instead of absorbing. Death by dehydration, they lose 1 L/hour

Question 19

What is osmotic diarrhea? What’s an example?

Answer 19

Gut lavage (golytely)
We don't have enzymes to break down the polyethylene glycol, so as it moves through the GI tract it continues to hold water

Question 20

What is exudative diarrhea? What’s an example

Answer 20

Shigella, salmonella, campylobacter

Destruction of the epithelial layer of the GI tract causes lousy absorption

Question 21

What is malabsorptive diarrhea? What’s an example?

Answer 21

Giardia, lymphatic obstruction, defective absorption, lactose intolerance
You consume something that can’t be broken down or absorbed, bacteria overgrows

Question 22

What’s an example of deranged motility diarrhea?

Answer 22

Surgery, hyperthyroidism

Question 23

Idiopathic inflammatory bowel disease: What is the difference between Crohn’s and Ulcerative Colitis?

Answer 23

Crohn’s: skip lesions, anywhere in GI tract, fissures instead of ulcers, fever, maybe rectal bleed, abdominal pain/mass, fistulas
UC: ulcers start at anus and goes back, pseudopolyps, rectal bleed, maybe abdominal tenderness

Question 24

Crohn’s/ UC symptoms?

Answer 24

Diarrhea, loss of appetite, weight loss, fatigue, painful and frequent BMs

Question 25

Diverticulitis/diverticulosis: what is it? What are the problems? What can someone do to prevent this?

Answer 25

Diverticula are pouches protruding out of the bowel, occurs in half of people over 50, increases with age
Problems: LLQ pain, bleeding, perforation, fistula formation after perforation
Treatment/prevention: eat more fiber

Question 26

What are 4 ways that bowel obstruction can occur mechanically?

Answer 26

Hernia
Adhesion
Intussusception (in kids, bowel folds into itself)
Volvulus (twists off)

Question 27

What are 3 types of pseudo-obstructions

Answer 27

Paralytic ileus
Bowel infarction
Myopathy, neuropathy (Hirschsprung)

Question 28

What is a polyp?

Answer 28

Tumorous mass protruding into the lumen

Question 29

Pedunculated vs sessile

Answer 29

Pedunculated: has a stalk (of tissue)
Sessile: not having a stalk

Question 30

Hyperplastic vs. Neoplastic

Answer 30

Hyperplastic: increased number of cells, not cancer
Neoplastic: abnormal disorganized growth, can be cancer

Question 31

Adenoma vs. adenocarcinoma?

Answer 31

Adenoma: neoplastic polyps arising from epithelial proliferation and dysplasia
Adenocarcinoma: cancer arising from adenomatous polyps (98% of colorectal cancers). It becomes invasive when it penetrates the muscularis mucosae and enters the submucosal layer.

Question 32

Colorectal cancer remains asymptomatic for a year, then what are the symptoms?

Answer 32

Pain obstruction, changes in bowel habit
Left side: blood in stool, LLQ pain
Right side: fatigue, weakness, iron deficient anemia (especially post-menopausal women with anemia)

Question 33

Colorectal carcinoma: _____ cases per year; _____ deaths in the USA; lifetime risk: 6% incidence; 2% death

Answer 33

150,000 cases per year

50,000 deaths