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Flashcards in GI Deck (57):
1

How do developmental anomalies affect the function of the digestive tract?

Both structural and functional

structural = anatomic development (largely 1st 3 fetal months)

e.g. cleft lip and esphagel atresia

functional = usually related to enzyme deficiency

e.g. abetalipoproteinemai

2

What is dental caries and how can it be prevented?

1. Begins as bacterial plaque

2. Leads to defect in enamel

3. Deeper defects allow entry of bacteria into pulp cavity

pulpitis = bacterial infection into the root canal

periodontal disease = gingival pockets

periapical granuloma= periapical bone

3

What are the main complications of dental caries?

Can extend to the root canal and invoke >> periapical ganuloma

Can extend to the jaw >> osteomyelitis

 

4

What causes periodontal disease?

Colonization of periodontal pockets with bacteria.

>> plaque formation >> calcification (tartar) >> gingival inflammation >> impedes blood supply to tooth

5

What is stomatitis, and what are its causes?

May be result of systemic disease, but also viruses, bacteria, fungi. 

C. albicans, herpes, canker sores

6

What is the significance of oral leukoplakia and erythroplakia?

Cancerous

7

What are the risk factors for oral cancer?

Is a complication of smoking, pipes, chewing tobacco

- also chronic alcoholism

- M > F

 

8

How does oral cancer present clinically?

- leukoplakia

- eyrthoplakia

- ulcer

-crater

- nodule/plaque

9

What is sialadenitis, and what are its causes?

Inflammation of the salivary glands

Either infectious or immune

Infectious: most commonly staph/strep

Immune: sjogren's syndrome (infiltrates of lymphocytes and plasma cells)

10

How does Sjogren's disease affect the salivary glands?

Enlarges gland >> infiltrates of lymphocytes and plasma cells >> glandular insufficiency (fibrosis)

11

Are salivary gland tumors mostly benign or malignant?

Major glands: Most are benign

 

Minor glands: 50% malignant

12

What is the most common salivary gland tumor?

pleomorphic adenoma

benign

- epithelial and myoepithelial 

13

What are the clinical signs and symptoms of esophageal disease?

- dysphagia

- esophageal pain
May be colic (spasmodic substernal pain) or retrosternal burning (heartburn)

- aspiration regurgitation

14

What is esophagitis, and what are its causes?

- infection: viruses and fungi (esp immunosuppressed)

- reflux of gastric juice: LES function compromised**

- exogenous irritants: swallowing of chemicals, etc

 

** Pepsin and HCl >> ulceration of squamous epithelium >> gets repaired by glandular (resembles columnar epithelium) >> foci of esophageal mucosa (metaplastic glandular epithelium) = Barret's esophagus

15

What is a hiatal hernia, and how does it present clinically?

= displacement of the cardiac portion of the stomach from the abdominal cavity into the thoracic cavity through the diaphragmatic hiatus

causes GERD

16

What is achalasia, and what are its causes?

spasm of the LES

dilation of the esophagus proximal  to spasm >> dysphagia, usually idiopathic

17

What is the most common cause of esophageal varices?

Caused by 

-cirrhosis of the liver

- portal HTN

* Malory weiss syndrome = occurs with strenuous vomiting (often alcoholic)

18

What are the risk factors for esophageal cancer and how do they account for the differences in the incidence of this disease in various parts of the world?

- High incidence: China, Iran, South Africa

- 3x more common in AA

- M > F (US), M = F (INTL)

- tobacco and alcohol use

 

19

Correlate the pathologic and clinical features of esophageal carcinoma.

Most originate from lower 1/3

- grow as endophytic or exophytic

Histology

Upper/middle 1/3 = squamous cell

Lower 1/3 = adenocarcinomas

20

What are the main forms of gastritis?

Acute and Chronic

Acute

- self limited

- shallow mucosal defects limited to upper layers of the epithelium
(erosions = superficial, ulcers = through mucosa)

 

Chronic

- atrophic (may have metaplasia, hyperplasia)

- predisposed to gastric cancer

21

What causes gastritis?

Acute

- caused by irritants or ischemia:

Curling's ulcer = assoc with burns >> bleeding

Cushing's ulcer = assoc with brain tumors >> large

 

Chronic

- H. pylori or immune

22

Explain the pathogenesis of peptic ulcer, placing special emphasis on the role of gastric juice, the mucosal barrier, and H pylori?

= mucosal ulceration extending through the entire gastric epithelial layer and into the muscularis

Can occur anywhere in the GI tract, but most often duodenum or stomach.

Causes

- gastric juice

- breakdown of mucosal barrier (increased by alcohol, smoking, stress, drugs)

- H. pylori (found in most patients with ulcer)

23

Describe the gross and microscopic pathology of peptic ulcer and correlate these morphologic findings with the clinical signs and symptoms of the disease.

 

Appear

- sharply punched out

- glandular amorphous material (bottom)

- "clean" d/t Hcl (no necrotic tissue)

Histology

- surface necrotic tissue

- zone of acute/chronic inflammation

- vascular granulation tissue

- fibrous scar tissue

24

What are the main complications of peptic ulcer?

1. Hemorrhage: usually causes melena, large ulcers can erode arteries >> massive bleeding

2. Penetration: can erode into pancreas >> pancreatitis

3. Perforation: intestinal hole >> peritonitis

4. Cicatrization: extensive scarring >> intestinal stenosis

25

How common is gastric cancer in the United States in comparison with the incidence of this neoplasm in other parts of the world?

Has decreased in the US.

8x lower than Japan/Chile

Likely due to decreased nitrosamines in US food (processing). Bacteria conver nitrate > nitrites > carcinogenic nitrosamines

26

How does gastric carcinoma present to the naked eye examination?

  1. superficial
  2. polypoid
  3. ulcerated
  4. diffuse carcinoma

27

Where do gastric carcinomas metastasize?

To regional lymph nodes to the LIVER

also through supraclavicular nodes (Virchow's)

- abdominal organs

- lungs

- bilateral ovaries (Krukenberg's tumor)

28

What are the clinical signs and symptoms of gastric carcinoma?

Nonspecific signs:

- weight loss
- anemia
- weakness

Local signs:
- gastritis
- vomiting
- loss of appetite
- dysphagia
- bleeding

29

How is gastric lymphoma related to MALT?

The lymphomas can originate in MALT . . . often related to H. pylori infection. 

*stomach = most common site

30

Compare atresia of the small intestine with Hirschbrung's disease.

atresia of the SI = complete obstruction of the lumen (must surgically resect)

 

hirschsprung's = lack of innervation (ganglion cells) >> permanent spasm. Prevents passage of feces, which accumulate proximal to the obstructed segment >> megacolon.

31

Describe diverticula of the large intestine and their complications.

outpouching of intestinal wall

(solitary/multiple, congenital acquired)

 

In the colon = protrusion of the mucosa/submucosa

complications >> perforation >> pericolonic abscess, fistulas, fibrosis, bleeding

32

Compare hemorrhoids and intestinal angiodysplasia.

Hemorrhoids = varicosities of anal/perianal region

External = below anorectal line

Internal = above anorectal line

 

Angiodysplasia = localized vascular lesion (colon)

dilated thin-walled BV that anastamose between arteries/veins in mucosa/submucosa

33

Compare occlusive and nonocclusive ischemic bowel disease.

occlusive = caused by thrombi/emboli

thrombus often found in superior mesenteric artery. Can lead transmural infarction of intestine >> high mortality

 

nonocclusive = atherosclerotic narrowing of arteries

scattered multiple infarcts >> hemorrhagic patches (ulcerate and become fibrotic)

34

How common is inflammatory bowel disease?

Ulcerative colitis 3x more common than Crohn's

- more common in whites, Jews

- peaks 20-30 yrs/o

- family predisposition

 

35

Compare Crohn's and ulcerative colitis.

Crohn's = chronic inflammation of the terminal ileum/colon

- begins with "apthous ulcers" over peyer's patches

- shallow mucosal defects >> transmural inflammation *often assoc. with granulomas

- fibrosis of muscularis and serosa = cobblestone appearance

>> strictures, adhesions >> fistulas

36

What is pseudomembranous colitis?

When balance between host and intestinal flora has been lost. 

e.g. c difficile after broad-spectrum antibiotics

- predominantly involves colon

- exotoxin of c diff acts on epithelial cells of the intestine >> ulcers (superficial) and focal necrosis

- ulcers covered wth layer of exudative fibrin, inflammatory cells, mucin = pseudomembranes

37

Compare diarrhea caused by small intestinal disease with diarrhea caused by large intestinal disease.

SI: large, watery, rarely have blood

LI: small, mucoid, commonly have blood, may have leukocytes

38

What are the clinical and pathologic features of acute appendicitis?

= usually caused by enterogenic bacteria that become pathogenic after obstruction of the lumen of the appendix

Bacteria become trapped >> multiply become noxious and cause ulceration

Sudden fever, leukocytosis, abdominal pain

39

Compare infectious and sterile peritonitis.

INFECTIOUS

= bacterial invasion of abdominal cavity

- rupture of stomach, abscess

- preexisting ascites

- infection from fallopian tubes

 

STERILE

= chemical irritation

- pancreatitis

- rupture of gallbladder

- postsurgical

40

Describe the pathogenesis and pathology of acute peritonitis.

serosal surface (intestines) and parietal peritoneum are congested and edematous

** exudate contains PMNs and fibrin >> fibrous adhesions

Symptoms: sharp abd pain, rebound tenderness, guarding. Intestines become paralzyed (high mortality)

41

List the most common causes of intestinal obstruction.

Paralytic ileus

or

Mechanical obstruction

- atresia
- stenosis
-strictures
- intussusception
- volvulus
- hernia
- adhesions
- neoplasms

42

What are the most common types of hernia?

Inguinal = most common

Inguinal: protrudes through inguinal canal or into scrotum

Femoral: occurs through femoral canal (groin)

Periumbilical: around umbilicus, ant abd wall

Diaphragmatic: through hiatus and exctends into thoracic cavity

 

43

Compare intussusception and volvulus.

intussusception = invagination of one segment of the intestine into another

compromised blood flow >> necrosis

 

volvulus = rotation around its mesenteric attachment site

twisting of arteries/veins >> infarction

44

Classify malabsorption syndromes according to their pathogenesis.

Inadequate intraluminal digestion

Primary mucosal absorptive defects

Impeded transport of nutrients

Pathologic

1. those that have characteristic findings

2. those that have non-specific findings
3. Those that have no pathologic findings

45

Compare celiac sprue and tropical sprue.

Celiac = hypersensitivity to gliadin in dietary grains

- SI shows mucosal atrophy with flattening of villi

- may develop T cell lymphoma

- affects proximal > distal intestine

 

Tropical = caused by bacteria

SI looks the same as Celiacs

- affects distal > proximal

- no allergy to gliadin

- responds to ABs

46

What are the clinical features of malabsorption syndrome?

Most prominent deficiencies = protein and lipids

protein (+ iron malabs) >> anemia

hypoalbuminemia >> edema

amenorrhea, impotence, muscle weakness

steatorrhea >> decreased vit ADKE

>> bleeding disorders

>> osteomalacia

47

How common are intestinal neoplasms and where are they most often located?

48

Classify intestinal neoplasms.

Non-neoplastic polyps

Neoplastic polyps

Malignant neoplasms

49

What are the risk factors for intestinal neoplasms?

Genetics: polyposis syndroms (FAB or Gardners, autosomal dominant), non-polyposis colorectal cancer

Diet: red meat, fat, refined carbs, lo vegetables

Oncogenes/TSG: TP53, KRAS; dysregulation of epithelial mucosal cells

 

50

What are polyps, and how are these intestinal lesions classified?

Polyps occur as the result of accumulation of irregular cells. They protrude into the lumen of the intestine
villous or tubular

 

 

51

Compare neoplastic and non-neoplastic polyps.

Non-neoplastic

Hyperplastic: most common, rectosigmoid area

Hamartoma: children < 5, retention polyps, peutz-jeghers (autosomal dominant)

Inflammatory: IBD, pseudopolyps

Neoplastic

Tubular: pedunculated polyps, cuboidal epithelium

Tubulovillous: predominantly tubular that appear villous 25%

Villous: sessile, fingerlike villi, lined with single nonclassifiable cell type

52

What are the clinical features of large intestinal cancer?

adenocarcinomas 50x more common in the LI

Early = no symptoms

Late = chronic blood loss, constpation, pencil-like feces, hematochezia, bleeding

53

Compare adenocarcinomas of the right and left colon.

right = intraluminal fungating or ulcerating masses

left = napkin ring stenotic lesions

54

What is CEA, and what is the clinical value of this tumor marker?

CEA is normally produced by embryonic intestine. In adult not found, except for special circumstances like regenerating epithelium of ulcerative colitis. 

CEA can be measured in serum . . . but is NOT useful for early detection or screening. Useful for recurrence.

55

How do carcinoids differ from adenocarcinoma of the large intestine?

Carcinoids = neuroendocrine tumors of low malignancy

- located in submucosa where they form small modules elevating the overlying mucosa)

- mostly small < 2cm

56

What is carcinoid syndrome?

When carcinoids metastasize to the liver, they release their secretory product into venous blood >>

symptoms: serotonin, bradykinin, histamine, bronchial wheezing, flushing, colic, diarrhea

57

Ulcerative colitis

Ulcerative colitis = intestinal inflammation (colon)

- starts with initial rectal lesions, spreads proximally

- mucosa with "sandpaper" appearance, prone to bleeding and infection

- atrophy of crypts + aggregate of leukocytes = crypt abcesses

- confluent ulcerations = serpiginous

- formation of pseudopolyps (residual, heavily inflamed mucosa)