Chapter 17-Small Intestine And Colon Flashcards
What is the most common cause of intestinal obstruction worldwide
Hernias
What are the common causes in the formation of adhesions
Surgical
Infection
Peritoneal inflammation
Endometriosis
What is the most common cause of herniations in the US
Adhesions
What is the most common cause of obstruction in patients under the age of 2
Intussusception
What are the two steps in the intestinal response to ischemic injury
1) Hypoxic injury due to vascular compromise
2) Reperfusion injury during restoration of blood
What are the watershed areas of the colon that are susceptible to ischemia
1) Splenic flexure (SMA and IMA)
2) Sigmoid Colon and rectum (IMA, pudundal, and iliac)
Which portion of the colon is prone to ischemic event, and which is more resistant
Surface epithelium is prone, while the crypts are more resistant
Transmural infarction is due to what
Acute arterial obstruction
What type of necrosis is seen in the ischemic events of the colon
Coagulative necrosis
When does ischemic disease of the colon commonly happen
After 70 years of age and in women
How does acute colonic ischemia typically present
Sudden onset of cramping, lower left abdominal pain, desire to dedicate and passage of blood or bloody diarrhea
Which portion of the colon is more severe with regards to an ischemic event
Right sided (mortality is doubled)
Which prognostic indicators prove to have a worse result with acute ischemia of the colon
-COPD and symptoms lasting 2 weeks
Why is the right side of the colon correlated with a worse prognosis
SMA supplies it, so its the first presentation of severe disease, such as the occlusion of the SMA
During radiation enterocolitis, what are the common clinical findings
- Radiation fibroblasts in the stroma
- anorexia
- Abdominal cramps
- Malabsorption diarrhea
What is the most common acquired GI emergency of neonates and what is the cause/presentation
Necrotizing enterocolitis aka transmural necrosis
- During low birth weight or prematurity
- Presents when oral feeding is initiated
When does Angio dysplasia present
After 60 years old
What is the cause of the angiodysplasia and where does it commonly occur
-Malformed submucosal blood vessels, and occurs in the right colon or cecum
What is a very important cause of malabsorption and diarrhea
Intestinal graft versus host disease after allogenic hematopoietic stem cell transplantation
What is the process of intraluminal digestion
Proteins, carbs, and fats are broken down into absorbable forms
What is the process of terminal digestion
Hydrolysis of carbs and peptides by disaccharidases and peptidases in the brush border
What is the process of transepithelial transport
Nutrients, fluid, and electrolytes are transported across and processed in the small intestine epithelium
What are the qualifications for secretory diarrhea
isotonic stool persisting during fasting
What are the qualifications for osmotic diarrhea
Excessive osmotic forces exerted by nonabsorpable luminal solutes
What are the qualifications for malabsorptive diarrhea
Failure of absorption, relieved with fasting
What are the qualifications of exudative diarrhea
Inflammatory disease in which purulent, bloody stool is continued during fasting
What does the lack of CTFR in CF lead to with regards to the pancreas
Dehydration leads to formation of pancreatic intraductual concretions
What is the process that celiac disease causes damage
-lymphocytes expressing NKG2D and MICA attack epithelium and allow gliadin through, which are attacked by CD4 T cells
What are the MHC compounds that are present with damage due to celiac disease
HLA-DQ2 and HLA-DQ8
Which portion of the Gi tract is normally diagnositic for Celiac
Second portion of duodenum
What are the histological findings for celiac disease
-Increased CD8, crypto hyperplasia, vilous atrophy
When do most cases of Celiac Disease present
30-60
Which gender is more common for celiac disease in adults
Women
What are extraintestinal complications associated with celiac disease
- Arthritis and joint pain
- aphthous stomatitis
- iron deficiency anemia
- delayed puberty
- Short stature
What are characteristic extraintestinal findings indicative of celiacs disease
Itchy, blistering skin lesion, dermatitis herpetiformis
A gluten free diet may reduce the risk of which conditions in those with celiac disease
- anemia
- female infertility
- osteoporosis
- cancer
What condition are those with celiac disease at a higher risk for
Aggressive malignancy in the form of enteropathy-associated T cell lymphoma
In some areas such as Australia, , Africa, Gambia, South America and Asia, what is a common cause of failure of oral vaccines
Environmental enteropathies such as tropical spruce.
In patients with IPEX, which autoantibodies are commonly present
Enterocytes, goblet cells, parietal cells, and islet cells
What is the heritability of lactase deficiency
Autosomal recessive
Abetalipoproteinemia is caused by a mutation in which gene
Microsomes triglyceride transfer protein (MTP)
What is the role of the MTP protein
-Transfers lipids to specialized domains o the aoplipoprotein B polypeptide within the Rough ER
What is the result of lack of MTP
Accumulation of intracellular lipids
What stain can be used to recognize Abetalipoproteinemia
Oil Red-O, especially after a fatty meal
What are the clinal presentations of Abetalipoproteinemia
Failure to thrive, diarrhea, and steatorrhea
What does the presence of a Anthonthocytic red cells characterize as
Aka burr cells in abetalipoproteinemia
Pediatric infectious diarrhea is commonly caused by which group of infectious agents
Enteric viruses
What is the location of cholera during an infection
Noninvasive and remains intralumenal
IN the case of cholera infection, what is the role of hemagglutinin
A metalloproteinase, for bacterial detachment and shedding in stool
IN the case of cholera infection, what part of the toxin is the effector and what does it bind to
Beta subunit binds to GM ganglioside to get endocytosed, but the A subunit activates the GCPR
What is the most common bacterial enteric pathogen in developed countries
C. Jejuni
What is a autoimmune complication with C. Jejuni and which MHC complex is it due to
Reactive arthritis, especially the HLA-B27
What are some common histological finding with campylobacter
Neutrophil infiltrates within the superficial mucosa, cryptitis, and crypt abscesses, but the architecture is preserved
What is the presentation of C jejuni in the clinical setting
Watery diarrhea, followed by a flu like prodrome as the primary symptom
What is the recommendation of antibiotic treatment for C jejuni
Not recommended
What are the physical features of shigellosis
Gram negative, non capsulated, non motile, facultative anaerobes
Which patients are likely to acquire shigellosis
Children in daycares, migrant workers, travelers, urging homes
What is the pathogenesis of Shigella
Taken up by M cells, proliferate intracellular, engulfed by macrophages and induce apoptosis.
Which toxin is secreted by shigella
Stx, part of the type 3 secretion system
Which portion of the GI tract is most affected by shigella
Left colon
Infection with which organism is commonly causes progression of water diarrhea into dysentery
Shigella
What are complications commonly seen with shigella and what is the HLA associated with
HLA-B27
- Sterile reactive arthritis
- Urethritis
- Conjunctivits
Which condition can occur following Shigella infection, and which other infection does it mimic
Mimics EHEC by the presence of hemolytic uremic syndrome
Which medication is contraindicated in Shella infection
Antidiarrheals
When is salmonella commonly seen
Younger children and older adults during the summer and fall
Chances of salmonella infection are increased in patients with which conditions
Decreased amounts of gastric acid
What is the recommendation of antibiotics in salmonella
Not recommended
What is the clinical features of salmonella
Fever (resolves in 2 days), but diarrhea for a week
Which patients have an increased risk of severe illness and complication as a result of salmonella
- Malignancies
- Immunosuppresion
- Alcoholics
- CV disease
- Sickle celled
- Hemplytic anemia
What is the location of colonization of typhus
Gallbladder
What is S typhi able to do thats different and what is the result systemically
-Disseminates via lymphatic fluid and blood, resulting in reactive hyperplasia of phagocytes
What is the result in the Peyer patches in a typhus infection
Enlargement in the terminal illeum in the form of elevated plateaus, along with the draining mesenteric LN
Morphologically, what is the damage seen in the GI tract
Oval ulcers, along the axis of the ileum with the risk of perforation
What are the findings in the spleen during a typhoid infection
Enlarged, soft, and uniformaly pale red pulp, obliterated follicular markings, and phagocytic hyperplasia
What are the findings in the liver during an typhoid infection
Typhoid nodules in the form of small, randomly scattered necrosis where hepatocytes are replaced by macrophages
What is the clinal course of infection with typhoid fever
- Anorexia, abdominal pain, bloating, nausea, vomiting, bloody diarrhea followed by a short asymptomatic phase
- Followed by bacteremi and fever with flu like symptoms
What can be seen on a physical exam during typhoid fever
Rose spots on the chest and abdomen
Patients with sickle celled diseases are prone to what complication with typhoid fever
Osteomyelitis
Increased levels of what in the blood stream are at greater risk for death and sepsis following infection with yersinia
Iron
Which preconditions increase the risk of death and sepsis with infection of yersinia
Anemia or hemochromatosis
What are the histological findings with yersinia
Regional LN and peyer patch hyperplasia, with bowel wall thickening
Which condition can yersinia infection mimic
Appendicitis
Which conditions are commonly seen during infection with yersinia
Pharyngitis
Arthralgia
Erythema nodosum
What is the principal cause of travelers diarrhea with regards to E. Coli
ETEC
What are the common symptoms with ETEC
Noninflammatory diarrhea, dehydration, and shock
Which patients are susceptible to ETEC
Children under 2
What are the proteins associated with virulence in EPEC
-Tir and espE gene
What is the recommendation for antibiotics during infection with EHEC
Not recommended.
What bacteria causes pseudomembranous colitis, and what is the common feature that allows the infection
C. Difficile and usually following antibiotic treatment
What is the pathogensis of C. difficile
Toxins activate Rho, leading to disruption of the epithelial cytoskeleton, tight junctions, and apoptosis
What are the risk factors for C. Difficile
Advanced age, hospitalization, antibiotic use
How will a patient with C. difficile present
Fever, leukocytosis, abdominal pain, cramps, watery diarrhea, cramps, and dehydration, leading to hypoproteinuremia
What is the histological finding in C. difficile
Volcano appearing as neutrophils leave the crypt
What is the method of detection of C. difficile
Toxin being present
What are the clinical findings of Whipple disease
Malabsorption, lymphadenopathy, arthritis of unknown causes
How common is Whipple disease
Rare
What are the diagnostic findings in Whipple disease
Foamy macrophages and large number of argyrphilic rods in the LN.
What is the cause of Whipple disease
Tropheryma whippelii
What is the stain use to diagnosis Whipple disease
PAS with diastase resistant granules
What stain should be used to confirm Whipple disease
Acid fast to rule out mycobacteria
What are the morpholigical findings in the case of Norovirus
Small intestine will have mild villi shortening, epithelial vacuolization, loss of brisk border, crypt hype trophy, and lamina propia lymphocytes infiltrating
Which patients are at increased risk of mortality due to norovirus
Immunosuppresed kidney transplant patients or graft versus host
What is the pathogensis of Rotavirus
Destroys the mature enterocytes of the small intestine, resulting in the villus surface to be repopulated by immature secretory cells
What is the toxin used by rotavirus
Nonstructural protein 4 (NSP4)
Which patients are commonly affected by adenovirus
Pediatrics and immunosuppressed
What type of parasite is ascaris lumbricoides
Nematode
What are the complications form ascaris lumbricoides
Obstruction of the intestine of biliary system
IN the cause of strongyloides, what is the pathogensis
Hatches in the intestine and then penetrates the mucosa.
Which complication arises from strongyloides
Autoinfection
What are the complications that arise from necator duodenale and ancylostoma duodenale
Superficial erosions, focal hemorrhages, inflammatory infiltrates, and iron deficiency anemia
What type of parasite is enterobius vermicularis
Pinworms
What is the pathogensis of enterobius vermicularis
Rarely serious complications, but deposit their eggs around the anus at night
What kinda of parasite is trichuris trichiura
Whipworms
What are the complications from trichuris trichiura
Very rarely, it can cause bloody diarrhea during heavy infections
What does schistosomiasis prefer to reside
Mesenteric veins
The intestinal cestodes can cause what complications
Normally do not cause them, but can cause diarrhea, nausea, and megaloblastic anemia (D. Latum)
What countries are common to see Entamoeba histolytica
India, Mexico, Columbia
What are of the GI tract does entamoabe histolytica commonly affect
Cecum, ascending colon
What is the characteristic of the histological finding of infection of entamoeba histolytica
Creates a flask shaped ulcer with a narrow neck and broad base
What are the complications with infection of entamoeba histolytica
Penetration of the splanchnic vessels which allow for embolization to the liver, forming abscesses
What are the characteristic finding of the liver abscesses in entamoeba histolytica
Scant inflammation at the margains, with shaggy fibrin lining
What is the most common parasite pathogen in humans
Giardia lamblia
What is the result of the infection with cryptosporidium
Sodium malabsorption
Chloride secretion
Nonblooddy, watery diarrhea
What is the irritable bowel syndrome (IBS) characterized by
Chronic, relapsing abdominal pain, bloating, and changes in bowel habits
What are some of the genome associations that have been liked to IBS
Serotonin reuptake transporters, cannabinol receptors, TNF related mediated
What has been effective for treatment for irritable bowel syndrome
5-HT3 receptor antagonists
What is the common patient group for irritable bowel syndrome
Females 20-40
What is the prognosis of irritable bowel syndrome (IBS) related to
Symptom duration, with longer duration linked to reduced likihood of improvement
What are the two conditions classified under IBD
Ulcerative colitis and Crohn disease
Which of the IBD conditions are transmural
Crohn disease
What is the age group the the IBD conditions will present
White Females in the Teens and early 20s
What is a genetic component strongly related to Crohns
NOD2 (nucleotide oligomerization binding domain 2)
In crohn disease, which cells are activated
CD4 as part of Th1
The barrier dysfunction associated with Crohns is due to which mutation
NOD2
What are the genes associated with ulcerative colitis
ECM1 (metalloproteinase 9
Which gene is associated with ulcerative colitis and maturity onset diabetes of the young
HNFA
Antibodies against what are present in Crohn’s disease what complications follow
-Against bacterial protein flagellum, seen in patients with NOD2, stricture formation, perforation, and small bowel
What is the morphological finding of Crohn’s disease
Cobblestone appearance that is depressed below the level of normal mucosa
-Creeping fat
What is a histological finding that is a hallmark of Crohn’s disease
Noncasseating granulomas
What are activities that can retrigger the events of crohns
Smoking, physical or emotional stress
What is the prevalence of fibrosis strictures in crohns and what is the clinical course of action
Very common in the terminal ileum and dealt by surgical resection
What is the treatment of Crohn’s disease
Anti TNF
What are the extraintestinal manifestations of crohns
-Uveitis
-Migratory polyarthriits
-sacroilitis
-ankylosis spondylitis
Erythema nodosum
-Clubbing of fingers
What two conditions commonly show with crohns or ulcerative colitis, but is more common in UC
- Pericholoangitis
- PSC
What does the long term outlook for patients with ulcerative cholitis depend on
Severity of active disease and disease duration
What is UC of the entire colon termed as
Pancolitis
In the cases of ulcerative colitis that develops toxic megacolon, what is the main concern
Perforation
What are the clinical presentations of ulcerative colitis
Relapsing disorder with attacks of bloody diarrhea with stringy, mucous material, lower abdominal pain, and cramps that are relieved by defications
The presence of perinuclear anti-neutrophil cytoplasmic antibodies are present in which condition
75% of Ulcerative colitis
Antibodies against saccaromyces cerevisiae are present in which condition
Crohns
What three factors with regards to IBD lead to increased chances of neoplasms
- Increased risk after 8 to 10 years
- Increased risk if pancolitis is present
- increased risk with more acute inflammation attacks
What is the feature of diversion colitis
- Mucosal erythema and friability
- numerous mucosal lymphoid follicles
What is diversion colitis
Inflammation of diverted segments of colon as a result of surgical resection due to another disease
What is treatment for diversion colitis
Enemas containing short chained fatty acids, which are a source for colonic epithelium
What are the characteristics of collagenous colitis
Increased collagen layer, lymphocytes and inflammation infiltrates in older women
What conditions are associated with lymphocytic colitis
-Celiac disease and autoimmune diseases:
Graves
RA
Autoimmune gastritis
What portions of the GI tract are commonly involved in graft versus host disease
Small bowel and colon
What is the most common histological finding of graft verses host in the GI
Epithelial apoptosis of crypt cells
What is the age group that commonly has diverticula disease
Older that 60 (extremely rare under 30)
What are the characteristics of diverticula disease
Not true diverticula as they do invest in all three layers
What is the cause of colonic diverticula
Elevated intraluminal pressure in the sigmoid colon causes pushing through focal discontinuities that nerves, vasa recta, and sheaths penetrate the inner circular muscle
Which portion of the colon is most common for false diverticulum
Sigmoid colon
What are the clinical presentations of diverticula disease
Intermittent cramping, continous lower abdominal discomfort, constipation, distention, alternating diarrhea and constipation
***Never being able to fully completely empty the rectum
What is required for the diagnosis of acute pancreatitis
Neutrophilic infiltration of the muscularis propria
How can an appendicitis be in the left upper quadrant
Malrotated colon
What are the complications with appendicitis
Pyelophlebitis
Portal vein thrombosis
Liver abscess
Bacteremia
Why is the appendix sometimes taken out even if healthy
Better than than the alternative of an appendix perforation
What is the most common tumor of the appendix
Well differentiated Neuroendocrine (carcinoid) tumor
What are the characteristics of the appendix
Always benign and in the distal tip
What is the condition of pseudomyxoma peritoneum
Mucocele forms in the appendix, leading to the abdomen filling with tenacious, semisolid mucin
What is the process of sterile peritonitis
Leakage of bile or pancreatic enzymes into the peritoneal cavity
What is the complication seen with perforation or rupture of the biliary system
Irritating peritonitis, complicated by bacterial superinfections
What is occurring with an acute hemorrhagic pancreatitis
Leakage of pancreatic enzymes and fat necrosis
What is a ruptured Desmond cysts leakage of chemical
Release of keratins and resulting granulomatous reaction
Spontaneous bacterial peritonitis develops in which patients
Cirrhosis, ascities, and children with nephrotic syndome
Sclerosing retroperitonitis aka Ormond disease is caused by what
Ig4
What is the most common tumor of the peritoneal lining
Desmoplastic small round cell
What are the tumors of the peritoneal lining characterized by with regards to translocations and gene
t(11;22)(p13;q12)
Fusion of EWS and WT1
