GI- Path- Non-neoplastic diseases of the intestines

Question 1

What are the 4 main causes of intestinal obstruction that make up 80%?

What other 2 causes make up the last 20%?

Answer 1

hernias, intestinal adhesions, intussusception, and volvulus

tumors and infarction

Question 2

What intervention is usually required in cases involving mechanical obstruction or severe infarction?

Answer 2

surgical

Question 3

What is the most common obstruction worldwide and 1/3 most common in US?

Answer 3

Hernias

Question 4

Any weakness or defect in the abdominal wall may permit protrusion of a serosa-lined pouch of peritoneum called a

Answer 4

hernia sac.

Question 5

Acquired hernias typically occur anteriorly/posteriorly, via the inguinal and canals, umbilicus, or at sites of surgical scars,

Answer 5

anterior

femoral

Question 6

Obstruction usually occurs because of visceral protrusion and is most frequently-associated with hernias, which tend to have narrow orifices and large sacs.

• Small bowel loops are typically involved, but or large bowel may also protrude, and any of these may become entrapped.

Answer 6

inguinal

omentum

Question 7

The resultant stasis from impaired venous drainage and edema increase the bulk of the herniated loop, leading to permanent entrapment (incarceration) and, over time, arterial and venous compromise (strangulation), and

Answer 7

infarction.

Question 8

Surgical procedures, infection, or other causes of peritoneal inflammation, such as endometriosis, may result in development of between bowel segments, the abdominal wall, or operative sites.

Answer 8

adhesions

Question 9

• are the most common cause of intestinal obstruction in the United States.*

Sequelae, include obstruction and strangulation.

Answer 9

Adhesions

Question 10

Twisting of a loop of bowel about its mesenteric point of attachment is termed ; it results in both luminal and vascular compromise.

can result in obstruction and .

Answer 10

volvulus

infarction

Question 11

Volvulus most often in large redundant loops of colon, followed in frequency by the cecum, small bowel, stomach, or, rarely, transverse colon

Answer 11

sigmoid

Question 12

Intussusception occurs when a segment of the intestine, constricted by a wave of peristalsis, into the immediately distal segment.

Once trapped, the invaginated segment is propelled by peristalsis and pulls the along.

Answer 12

telescopes

mesentery

Question 13

Intussusception is the most common cause of intestinal obstruction in children less than years of age.

Answer 13

2

Question 14

Instussusception is associated with viral infection, rotavirus vaccines, reactive of Peyer’s patches

Answer 14

hyperplasia

Question 15

are diagnostically useful and also are effective in correcting idiopathic intussusception in infants and young children.

• Surgical intervention is necessary when an intraluminal or

serves as the initiating point of traction, as is typical in older children and in adults

Answer 15

Contrast enemas

mass

tumor

Question 16

What is a mural infarction?

Answer 16

An infarction of the mucosa and the submucosa

Question 17

While mucosal or mural infarctions often are secondary to acute or chronic , transmural infarction is generally caused by vascular obstruction.

Answer 17

hypoperfusion

acute

Question 18

Important causes of acute arterial obstruction include severe (which is often prominent at the origin of mesenteric vessels), aortic aneurysm, hypercoagulable states, oral contraceptive use, and embolization of cardiac or aortic atheromas.

Answer 18

atherosclerosis

vegetations

Question 19

What two aspects of intestinal vascular anatomy contribute to the distribution of ischemic damage?

Answer 19

• Watershed zones
• Patterns of intestinal microvessels

Question 20

intestinal segments at the end of their respective arterial supplies that are particularly susceptible to ischemia, the splenic flexure (SMA-IMA) and the sigmoid colon and rectum (IMA, pudendal, and Iliac a.) ?

Answer 20

watershed zones

Question 21

Generalized or hypoxemia can cause localized injury at these sites, and ischemic disease should be considered in the differential dx for focal colitis of the flexure or colon

Answer 21

hypotension

splenic

rectosigmoid

Question 22

Why is the surface epithelium particularly vulnerable to ischemic injury?

Answer 22

Intestinal capillaries run alongside the glands, from crypt to surface, before making a hairpin turn at the surface

Question 23

surface epithelial atrophy, or even necrosis and epithelial sloughing, with normal or hyperproliferative crypts is a morphologic signature of

disease.

Answer 23

ischemic intestinal

Question 24

Infarction is frequently segmental and patchy.

• The mucosa is hemorrhagic and often .*

Answer 24

ulcerated

Question 25

Answer 25

Dead bowel

Question 26

ischemic intestine demonstrates atrophy or sloughing of surface epithelium. * The crypts may be * Inflammatory infiltrates are initially absent in acute ischemia, but are recruited within hours of reperfusion.

Answer 26

hyperproliferative. neutrophils note: the neutrophils and the sloughing up top

Question 27

ischemia is accompanied by fibrous scarring of the lamina propria and, uncommonly, stricture formation.

Answer 27

Chronic note: notice the scarring of the lamina propria in light pink

Question 28

Ischemic bowel disease tends to occur in **younger/older** adults with coexisting cardiac or vascular disease.

Answer 28

older

Question 29

Acute transmural infarction typically manifests with sudden, severe abdominal pain and tenderness, sometimes accompanied by nausea, vomiting, bloody diarrhea, or grossly stool

Answer 29

melanotic

Question 30

Acute transmural infarction may progress to shock and vascular collapse within hours as a result of loss. • sounds diminish or disappear, and muscular spasm creates **boardlike rigidity of the abdominal wall**

Answer 30

blood Peristaltic

Question 31

What other 3 abdominal emergencies resemble ischemic bowel disease?

Answer 31

acute appendicitis, perforated ulcer, and acute cholecystitis,

Question 32

As the mucosal barrier breaks down, bacteria enter the circulation and can develop; the mortality rate in these cases may exceed 50%.\*

Answer 32

sepsis

Question 33

What is characterized by **malformed submucosal and mucosal blood vessels**, occurs most often in the **cecum or right colon**, and usually presents after the sixth decade of life? • Although it affects less than 1% of the adult population, accounts for 20% of major episodes of lower intestinal bleeding.

Answer 33

angiodysplasia

Question 34

What are dilated anal and perianal collateral vessels that connect the portal and caval venous systems to relieve elevated venous pressure within the hemorrhoid plexus?

Answer 34

hemorrhoids

Question 35

What are some predisposing factors for hemorrhoids?

Answer 35

constipation increased intraabdominal and venous pressure venous stasis of pregnancy portal hypertension

Question 36

Collateral vessels within the hemorrhoidal plexus are located below the anorectal line and are termed external hemorrhoids, while those that result from dilation of the hemorrhoidal plexus within the distal rectum are referred to as internal hemorrhoids

Answer 36

inferior superior

Question 37

sclerotherapy, rubber band ligation, and infrared coagulation are treatments for which condition?

Answer 37

hemorrhoids

Question 38

Systemic vasculitides and infectious diseases (CMV) can cause vascular disease that **is/is not** confined to the gastrointestinal tract.

Answer 38

is not

Question 39

What disease refers to acquired pseudodiverticular outpouchings of the colonic mucosa and submucosa? rare in individuals younger than 30 years of age, but the prevalence approaches 50% in Western adult populations older than years of age.

Answer 39

Diverticular disease 60

Question 40

Diverticula generally are multiple, and the condition is referred to as

Answer 40

diverticulosis. less common in developing countries,

Question 41

Colonic diverticula tend to develop under conditions of elevated pressure in the sigmoid colon

Answer 41

intraluminal

Question 42

Why is diverticulosis more common in the colon?

Answer 42

the colon, this muscle layer is discontinuous, being gathered into three bands termed taeniae coli.

Question 43

High luminal pressures may be generated by exaggerated peristaltic contractions, with spasmodic sequestration of bowel segments that may be exacerbated by diets low in which reduce stool bulk.

Answer 43

fiber

Question 44

Anatomically, colonic diverticula are small, flasklike outpouchings, usually 0.5 to cm in diameter, that occur in a regular distribution in between the taeniae coli. • They are most common in the colon, but other regions of the colon may be affected.

Answer 44

1 sigmoid

Question 45

Colonic diverticula have a thin wall composed of a or atrophic mucosa, compressed submucosa, and attenuated muscularis propria - often, this last component is totally absent

Answer 45

flattened

Question 46

Because the wall of the diverticulum is supported only by the muscularis mucosa and a thin layer of subserosal adipose tissue, inflammation, increased pressure, and mucosal ulceration within an obstructed diverticulum can readily result in

Answer 46

perforation.

Question 47

Concerning diverticular disease: Most individuals with diverticular disease remain **asymptomatic/symptomatic** complaints including intermittent cramping, continuous lower abdominal discomfort, constipation, and most often resolves spontaneously or after treatment, and relatively few patients require surgical intervention

Answer 47

asymptomatic diarrhea antibiotic

Question 48

What is a chronic condition resulting from complex interactions between intestinal microbiota and host immunity in genetically predisposed individuals resulting an inappropriate mucosal immune activation?

Answer 48

Inflammatory bowel disease (IBD)

Question 49

What are the 2 types of IBD?

Answer 49

Crohn disease and ulcerative colitis.

Question 50

Review differences between IBD and Crohn's

Answer 50

Question 51

is limited to the colon and rectum and extends only into the mucosa and submucosa. ## Footnote , aka regional enteritis (because of frequent ileal involvement), may involve any area of the gastrointestinal tract and is frequently transmural.

Answer 51

Ulcerative colitis Crohn disease

Question 52

When do Crohn disease and ulcerative colitis frequently present:

Answer 52

mostly adolescence or in young adults after the fifth decade

Question 53

IBD is most common among whites and is 3 to 5 times more often among eastern

Answer 53

European (Ashkenazi) Jews.

Question 54

Most investigators believe that IBD results from the combined effects of alterations in host interactions with intestinal , intestinal epithelial , aberrant mucosal immune responses, and altered composition of the gut microbiome.

Answer 54

microbiota dysfunction

Question 55

Genetic factors are more prominant in Crohn's/UC?

Answer 55

Crohn's

Question 56

Molecular linkage analyses of affected families have identified (nucleotide oligomerization binding domain 2) as a susceptibility gene in Crohn disease.

Answer 56

NOD2

Question 57

NOD2 encodes a protein that binds to intracellular bacterial and than activates NF-κB. NOD-2 mutation is ineffective at defending against intestinal bacteria. • The result is that bacteria are able to enter through the epithelium into the wall of the intestine, where they trigger reactions.\*

Answer 57

peptidoglycans inflammatory

Question 58

What other genes are associated with IBD other than NOD 2? autophagosome pathway and, like NOD-2, are involved in host cell responses supporting the hypothesis that inadequate defense against luminal bacteria may be important in the pathogenesis of IBD

Answer 58

ATG16L1 (autophagy-related 16–like-1) and IRGM (immunity-related GTPase M) genes.

Question 59

immunosuppressive and agents remain mainstays of IBD therapy.

Answer 59

immunomodulatory

Question 60

Polarization of helper T cells to the TH1 type is recognized in disease, and some data suggest that TH17 T cells also contribute to disease pathogenesis.\*

Answer 60

Crohn

Question 61

Some data suggest that mucosal production of the TH 2- derived cytokine IL-13 is increased in and, to a lesser degree, Crohn disease

Answer 61

ulcerative colitis

Question 62

defects in intestinal epithelial barrier function occur in patients with Crohn disease and a subset of their healthy first-degree relatives

Answer 62

tight junction

Question 63

One model that unifies the roles of intestinal microbiota, epithelial function, and mucosal immunity suggests a cycle by which flux of luminal bacterial components activates innate and adaptive immune responses.

Answer 63

transepithelial

Question 64

In a genetically susceptible host, the subsequent release of and other immune signals directs epithelia to increase tight junction permeability, which further increases the flux of luminal material

Answer 64

TNF

Question 65

Crohn disease, also known as regional enteritis, may occur in any area of the gastrointestinal tract but the most common sites involved at presentation are the terminal ileum, ileocecal valve, and .

Answer 65

cecum

Question 66

The presence of multiple, separate, sharply delineated areas of disease, resulting in , is characteristic of Crohn disease and may help in differentiation from ulcerative colitis.

Answer 66

skip lesions

Question 67

The earliest lesion, the ulcer, may progress, and multiple lesions often coalesce into elongated, serpentine ulcers oriented along the axis of the bowel. • Sparing of interspersed mucosa results in a coarsely textured, appearance in which diseased tissue is depressed below the level of normal mucosa. • frequently develop between mucosal folds and may extend deeply to become sites of perforation or fistula tracts

Answer 67

aphthous cobblestone Fissures

Question 68

The intestinal wall is thickened as a consequence of edema, inflammation, submucosal fibrosis, and hypertrophy of the muscularis propria, all of which contribute to stricture formation. • In cases with extensive transmural disease, frequently extends around the serosal surface (creeping fat)

Answer 68

transmural mesenteric fat

Question 69

The microscopic features of active Crohn disease include abundant that infiltrate and damage crypt epithelium. * Clusters of within a crypt are referred to as a crypt abscess and often are associated with crypt destruction. * Ulceration is common in Crohn disease, and there may be an abrupt transition between ulcerated and normal mucosa. * Repeated cycles of crypt destruction and regeneration lead to distortion of mucosal ; the normally straight and parallel crypts take on bizarre branching shapes and unusual orientations to one another

Answer 69

neutrophils neutrophils architecture

Question 70

What is a hallmark of Crohn disease, are found in approximately 35% of cases and may arise in areas of active disease or uninvolved regions in any layer of the intestinal wall?

Answer 70

Noncaseating granulomas

Question 71

What are some of the many symptoms of Crohn's

Answer 71

relatively mild diarrhea, fever, and abdominal pain. right lower-quadrant pain and fever bloody diarrhea

Question 72

Concerning Crohn's, Disease reactivation can be associated with a variety of external triggers, including physical or emotional , specific dietary items, NSAID use, and smoking

Answer 72

stress cigarette

Question 73

-deficiency anemia may develop in individuals with Chrohn's colonic disease. Extensive small-bowel disease may result in serum loss and hypoalbuminemia, generalized nutrient malabsorption, or malabsorption of vitamin and bile salts.

Answer 73

Iron protein B12

Question 74

Fibrosing particularly of the terminal ileum, are common and require surgical resection. • Disease often recurs at the site of , and as many as 40% of patients require additional resections within 10 years.

Answer 74

strictures, anastomosis

Question 75

As concerning Crohn's develop between loops of bowel and may also involve the urinary bladder, vagina, and abdominal or perianal skin. • Perforations and peritoneal can also occur.

Answer 75

Fistulas abscesses

Question 76

Extraintestinal manifestations of Crohn disease include , **migratory polyarthritis, sacroiliitis, ankylosing spondylitis, erythema nodosum, and clubbing of the fingertips**, any of which may develop before intestinal disease is recognized.

Answer 76

uveitis

Question 77

Pericholangitis and primary sclerosing cholangitis may occur in Crohn disease but are more common in

Answer 77

ulcerative colitis

Question 78

The risk for development of colonic is increased in patients with long-standing colonic Crohn disease

Answer 78

adenocarcinoma

Question 79

What always involves the rectum and extends proximally in a continuous fashion to involve part or the entire colon that can be diffusely ulcerated. • Skip lesions are not seen.

Answer 79

Ulcerative colitis

Question 80

Disease of the entire colon is termed * Disease limited to the rectum or rectosigmoid may be referred to descriptively as ulcerative or ulcerative proctosigmoiditis. * The small intestine is normal, although mild mucosal inflammation of the distal ileum, , may be present in severe cases of pancolitis.

Answer 80

pancolitis. proctitis backwash ileitis

Question 81

Grossly, involved colonic mucosa may be slightly red and granularappearing or exhibit extensive broad-based ulcers. * The transition between diseased and uninvolved colon can be * Isolated islands of regenerating mucosa often bulge into the lumen to create small elevations, termed

Answer 81

abrupt. pseudopolyps.

Question 82

Concerning ulcerative colitis Chronic disease may lead to mucosal and a flat, smooth mucosal surface. * Unlike in Crohn disease, mural thickening is absent, the serosal surface is normal, and strictures do not occur. * Inflammation and inflammatory mediators can damage the muscularis propria and disturb neuromuscular function leading to colonic dilation and toxic , which carries a significant risk for perforation.

Answer 82

atrophy megacolon

Question 83

inflammatory infiltrates, crypt abscesses, crypt distortion, and epithelial metaplasia are both in UC and Crohns However Skip lesions and granulomas are not present in UC/Crohns?

Answer 83

UC

Question 84

is a relapsing disorder characterized by attacks of bloody diarrhea with expulsion of stringy, mucoid material and lower abdominal pain and cramps that are temporarily relieved by defecation.

Answer 84

Ulcerative colitis

Question 85

With UC, the onset of symptoms can occur shortly after smoking in some patients, and smoking may partially relieve symptoms.

Answer 85

cessation

Question 86

Extraintestinal manifestations of UC, similar to Crohn's:

Answer 86

migratory polyarthritis, sacroiliitis, ankylosing spondylitis, uveitis, skin lesions, pericholangitis, and primary scleros­ing cholangitis.

Question 87

In UC, colectomy cures intestinal disease, but extraintestinal manifestations **may/may not** persist

Answer 87

may

Question 88

What 3 factors are related to the development of colitis associated dysplasia:

Answer 88

**Duration of disease** - Risk increases beginning 8-10 years after disease initiation. • **Extent of involvement** - Patients with pancolitis are at greater risk than those with only left-sided disease. **• Inflammation** - Greater frequency and severity of active inflammation (characterized by the presence of neutrophils) may increase risk.

Question 89

Those with UC and what other condition have greater risk of developing dysplasia?

Answer 89

primary sclerosing cholangitis

Question 90

Acute appendicitis is most common in and young adults but may occur in any age group. **Females/Males** are affected slightly more may be confused with mesenteric lymphadenitis, acute salpingitis, ectopic pregnancy, mittelschmerz (pain associated with ovulation), and Meckel diverticulitis.

Answer 90

adolescents Males

Question 91

Acute appendicitis is thought to be initiated by progressive increase in intraluminal pressure that compromises outflow. * In 50%-80% of cases, acute appendicitis is associated with overt luminal obstruction, usually by a small, stone-like mass of stool, or , or, less commonly, a gallstone, tumor, or mass of worms. * Ischemic injury and stasis of luminal contents, which favor bacterial , trigger inflammatory responses including tissue edema and neutrophilic infiltration of the lumen, muscular wall, and periappendiceal soft tissues.

Answer 91

venous fecalith proliferation

Question 92

In early acute appendicitis, subserosal vessels are congested, and a modest perivascular neutrophilic infiltrate is present within **some/all** layers of the wall. * The inflammatory reaction transforms the normal glistening serosa into a , granular-appearing, erythematous surface. * The diagnosis requires infiltration of the muscularis propria.

Answer 92

all dull neutrophilic

Question 93

In more severe cases, focal abscesses may form within the wall, and these may even progress to large areas of hemorrhagic ulceration and gangrenous necrosis that extend to the serosa, creating acute appendicitis, which often is followed by rupture and suppurative

Answer 93

gangrenous peritonitis.

Question 94

Typically, early acute appendicitis produces periumbilical pain that ultimately localizes to the lower quadrant, followed by nausea, vomiting, low-grade fever, and a mildly elevated peripheral white blood cell count. • A classic physical finding is sign, deep tenderness noted at a location two-thirds of the distance from the umbilicus to the right anterior superior iliac spine (McBurney's point).

Answer 94

right McBurney's