Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
Name 4 initiating events that lead to bowel inflammation
|
1. Infection
2. Ischemia 3. Radiation 4. Chemical Toxins |
|
Describe the time course for wound healing as it applies to the bowel
|
1. Clot formations/Resolution
(Fibrinolysis inc.) 2. Inflammation (Macs and PMNS inc.) 3. Epithelial Healing (Restitution+Proliferation/Maturation) 4. Granulation Tissue Formation |
|
The organization of the gut-associated lymphoid tissue.
A ________ contains a special follicle associated epithelium or "___ cells” overlies the lymphoid tissue. |
Peyer’s patch
M |
|
T/F
M cells take up molecules and particles from the gut lumen by endocytosis or phagocytosis. This material is then transported through the interior of the cell in vesicles to the basal cell membrane, where it is released into the extracellular space. ------------------ This process is known as |
True
Transcytosis |
|
Mucosal Immunity:
The afferent immune response. Antigen from pathogenic microorganisms is presented beneath mucosal surfaces to ______ lymphocytes within organized mucosal lymphoid tissue, for example _________. Activated lymphocytes leave this tissue via draining lymph nodes and reenter the circulation through the _________. |
naïve
Peyer’s patches thoracic duct |
|
Mucosal Immunity
Efferent immune response T/F Primed lymphocytes reenter mucosal tissues throughout the body from the circulation, thereby disseminating a mucosal immune response |
True
|
|
Mucosal Immunity
Polymeric ____ is transported into the gut lumen through epithelial cells at _________________ |
IgA
at the base of the crypts |
|
Mucosal Immunity
Polymeric IgA binds to the _______ layer overlying the gut epithelium |
mucus layer
|
|
Effector T cells home to the gut by combinations of relatively specific interactions involving adhesion molecules and chemokines.
a gut-homing lymphocyte adheres to the vascular endothelium of an intestinal blood vessel by the binding of lymphocyte ________ to MAdCAM-1 expressed on the endothelial surface. |
L-selectin and α4:β7 integrin
|
|
T/F
Interaction between the T-cell integrin α4:β7 and epithelial E-cadherin weakens T-cell localization to the intestinal epithelium. |
False
Interaction between the T-cell integrin α4:β7 and epithelial E-cadherin STRENGTHENS T-cell localization to the intestinal epithelium. |
|
Inflammatory Bowel Disease
Ulcerative colitis |
produces colonic mucosal inflammation with small shallow ulcers, presents with bloody diarrhea, and involves ONLY the colon.
Ulcerative colitis confined to the rectum is termed ulcerative proctitis. |
|
Inflammatory Bowel Disease
Crohn's disease Regional enteritis (Crohn's) Enterocolitis (Crohn's) Definitions: |
- produces transmural intestinal inflammation with granulomatous and inflammatory masses, and can occur anywhere in the gastrointestinal tract.
- If it involves only the small bowel, we use the term regional enteritis - refers to both colonic and small bowel involvement. |
|
IBD
Presentation: UC vs. CD Age of Onset: Diarrhea: Abdominal Pain: Fever Anorexia: (These illustrate Similarities) |
Age of Onset:
Both, any age: Peak 10-35 Diarrhea: UC: Common: 80-95%; CD: Common: 70-90% Abdominal Pain: UC: 15-60% (mild); CD: 70-80% (moderate-severe) Fever UC: Less Frequent; CD: more frequent Anorexia: UC: Weight loss = 20-60% (mild); CD: 45-70% (weight loss may be severe) |
|
Case 1.
Mr. C.F. is a 24-year-old white male with a six week history of bloody diarrhea (10-12 loose movements per day) and lower abdominal cramps relieved by the passage of small amounts of mucus. He is awakened at night with the pain and diarrhea, has had a marked loss of appetite, and has had an intermittent, low grade fever (100°F). Physical exam reveals a slightly tender abdomen, and fresh blood in the rectum. A 12-pound weight loss has occurred since a physical exam two years previously. There are no palpable masses. |
Ulcerative Colitis
|
|
Case 2.
Mrs. J.R. is a 19-year-old white female with diarrhea and lower abdominal cramps for four months. During the past four months she has had 5-10 loose watery stools per day with no bleeding, has occasionally been awakened at night with cramps relieved by defecation, and, on two occasions, has had several days of malaise and fever (up to 101°F, orally). She has felt a frequent nagging sensation in the right lower quadrant, which does not radiate, and has noted protruding hemorrhoids plus occasional excruciating pain on defecation. Physical exam reveals a fullness in the right lower quadrant, painful external hemorrhoids, a rectal fissure, and a temperature of 100.8°F. |
Crohn's Disease
|
|
Differences in Presentation:
Ulcerative Colitis vs. Crohn's Disease Rectal Bleeding Anal Lesions (fissures, fistulas) Rectal Involvement Abdominal Mass (Differences) |
Rectal Bleeding:
UC: Common: 70-100% CD:Occasional: 10-20% (especially with colitis) Anal Lesions (fissures, fistulas) UC: Unusual CD:Common Rectal Involvement UC: More than 95% CD: Less than 50% Abdominal Mass UC: Rare CD: Common |
|
Inflammatory Bowel Disease
C. Differential Diagnosis. |
- Infectious diseases
amebiasis, shigellosis, salmonellosis, enteropathogenic E. coli, yersinia enterocolitis, giardiasis, tuberculosis, and viral enteritis. - Drug induced: pseudomembranous colitis, drug allergy (e.g. penicillin allergy) and laxative abuse. - Ischemic colitis vascular insufficiency, and radiation colitis: present with manifestations similar to ulcerative colitis. Radiation enteritis can mimic Crohn's disease. - Diverticulitis, carcinoma, polyps and familial polyposis are included in the differential diagnosis in patients with rectal bleeding and/or abdominal pain - Irritable bowel syndrome (exclusion) |
|
Differential diagnosis of Crohn’s disease.
|
Appendicitis
Tuberculosis Lymphoma |
|
Differential Diagnosis of Ulcerative Colitis
|
Enteric infections: Shigella, E. Coli, Salmonella, Campylobacter, Ameba, Yersinia
Pseudo membranous colitis Ischemic colitis Diverticulitis Hemorrhoids |
|
CD vs. UC
Microscopic distribution differences |
UC is diffuse and stricly a mucosal disease - deeper muscularis layer = normal
CD is segmental and involves all layers of colon and wall (transmural) |
|
T/F
Granulomas are more commonly found in UC |
False
Granulomas are more commonly found in CD |
|
Some Microscopic Differential Points.
CD vs. UC Inflammation Crypt abscess Granulomata Fissures Lymph node Location |
Inflammation
UC: Mucosal CD: Transmural Crypt abscess UC: Common CD: Uncommon Granulomata UC: Rare CD: Common: 60-70% Fissures UC: Rare CD: Common Lymph node UC: Hyperplasia CD: Granulomata Location UC: Colon CD: Anywhere in GI tract mouth, duodenum, jejunum, ileum, colon |
|
Some Radiographic Differential Points
CD vs. UC Distribution Rectum Terminal ileum Mucosa Strictures or fistula |
Distribution
UC: Continuous with rectum CD: Discontinuous and segmental anywhere in GI tract: especially small bowel and colon Rectum UC: Almost always involved CD: Often normal Terminal ileum UC: Usually normal CD: Often involved: stenotic and irregular Mucosa UC: Often involved: stenotic and irregular CD: Big longitudinal fissures "Cobblestone" appearance Strictures or fistula UC: Rare CD: Frequent |
|
Some Differences in Long-Term Complications and Courses
CD vs. UC Colonic Cancer Toxic megacolon Massive hemorrhage Strictures Internal fistulas |
Colonic Cancer
UC: Markedly increased in high risk patients CD: Slightly increased in granulomatous colitis Toxic megacolon UC: 5-10% CD: Uncommon but can occur Massive hemorrhage UC: 3% CD: Uncommon but can occur Strictures UC: Uncommon CD: Very common (obstruction) Internal fistulas UC: Uncommon CD: Common |
|
Some Differences in Long-Term Complications and Course.
UC vs.CD. Anorectal complications Perianal abscess Surgical cure |
Anorectal complications
UC: Occasional CD: Common Perianal abscess UC: 3-4% CD: Common Surgical cure UC: Yes CD: No-disease recurs elsewhere |
|
Inflammatory Bowel Disease
Etiology and Pathogenesis. |
1. Genetic
The single most important risk factor is a first degree relative with the disease. 2. Environmental/Infectious 3. Immunologic There is prolonged immune activation with infiltration with lymphocytes and macrophages and increased production of IgG. |
|
NOD2/CARD15 mutations
|
NOD2/CARD15 is part of the innate immune system that recognizes bacterial products -
50% of patients with Crohn's disease have mutations in NOD2 but having NOD2 mutations doesn't necessarily mean you will have Crohn's |
|
Treatment.
Ulcerative colitis: |
1. Anti-inflammatory drugs.
a. NSAIDs are not useful. b. 5-aminosalicylate and sulfasalazine are useful in mildly active disease and in inactive disease to prevent relapse. Mechanism of action is unknown; however, they are free radical scavengers and inhibit leukotriene synthesis. c. Corticosteroids. Effective in reducing inflammation, but disease tends to relapse when drug is withdrawn. 2. Immunosuppressive drugs. a. 6-mercaptopurine. b. Cyclosporine. 3. Colectomy is curative. |
|
Treatment.
Crohn's Disease: |
1. Anti-inflammatory drugs.
a. NSAIDs are not effective. b. 5-aminosalicylate and sulfasalazine are effective for mildly active disease especially in the colon. c. Corticosteroids. Same as for ulcerative colitis. 2. Immunosuppressive drugs. a. 6-mercaptopurine. b. Cyclosporine. 3. Surgery. Useful for tight strictures, abscesses and fistulae. Resection of involved area is not curative: disease usually recurs in previously normal gut. |