Term
| What is a hernia and where does it most commonly occur? |
|
Definition
Any weakness or defect in the wall of the peritoneal cavity may permit protrusion of a serosa-lined pouch of peritoneum called a hernia sac.
Acquired hernias most commonly occur anteriorly, via the inguinal and femoral canals or umbilicus, or at sites of surgical scars |
|
|
Term
| What is external herniation? And how does it relate to incarceration and strangulation? |
|
Definition
External herniation is a visceral protrusion. Pressure at the neck of the pouch may impair venous drainage of the entrapped viscus.
Incarceration: stasis and edema increase the bulk of the herniated loop leading to permanent entrapment
Strangulation: arterial and venous compromise that develops and can result in infarction |
|
|
Term
|
Definition
| Adhesions, or fibrous bridges between bowel segments can create closed loops through which other viscera may slide and become entrapped. Obstruction and strangulation are similar to external hernia |
|
|
Term
| Where does volvulus most often occur? |
|
Definition
| in large redundant loops of sigmoid colon, followed in frequency by the cecum, small bowel, stomach, or, rarely transverse colon |
|
|
Term
| What are the initial responses to ischemia in ischemic bowel disease? |
|
Definition
1. hypoxic injury: occurs at onset of vascular compromise
2. reperfusion injury: initiated by restoration of the blood supply and it is at this time that the greatest damage occurs |
|
|
Term
| What are 2 aspects of intestinal vascular anatomy that contribute to the distribution of ischemic damage? |
|
Definition
1. Intestinal segments at the end of their arterial supplies are particularly susceptible to ischemia. Called "watershed zones"
2. Intestinal capillaries run alongside the glands from crypt to surface before making a hairpin turn at the surface to empty into the post-capillary venules leaving surface epithelium vulnerable to ischemic injury |
|
|
Term
| What are some underlying causes of ischemic bowel disease? |
|
Definition
More common in older individuals with coexisting cardiac or vascular disease.
Causes: mucosal and mural infarctions, chronic ischemia, CMV infection, radiation enterocolitis, necrotizing enterocolitis |
|
|
Term
| How do you characterize angiodysplasia? |
|
Definition
| Malformed submucosal and mucosal blood vessels. It occurs most often in the cecum or right colon usually after the 6th decade of life |
|
|
Term
| How does malabsorption most commonly present and what is a hallmark of it? |
|
Definition
Most commonly presents as chronic diarrhea
Hallmark is steatorrhea, characterized by excessive fecal fat and bulky frothy, greasy, yellow or clay-colored stools |
|
|
Term
| What are the chronic malabsorptive disorders most commonly encountered in the US? |
|
Definition
| pancreatic insufficiency, celiac disease, and crohn disease |
|
|
Term
| What are the 4 types of diarrhea? |
|
Definition
1. secretory- characterized by isotonic stool and persists during fasting
2. Osmotic - occurs with lactase deficiency, due to excessive osmotic forces exerted by unabsorbed luminal solutes
3. malabsorptive- associated with steatorrhea, relieved by fasting
4. exudative diarrhea- due to inflammatory disease and characterized by purulent, bloody stools that continue during fasting |
|
|
Term
| What is the difference between silent celiac and latent celiac disease? |
|
Definition
1. Silent- positive serology and villous atrophy without symptoms
2. Latent- positive serology is not accompanied by villous atrophy |
|
|
Term
| What are key clinical features of celiacs? |
|
Definition
1. Detected more commonly in WOMEN
2. Extra-intestinal complaints- arthritis or joint pain, seizure disorders, aphthous stomatitis, iron deficiency anemia, pubertal delay, short stature
3. dermatitis herpetiformis- characteristic itchy blistering skin lesion |
|
|
Term
| What are the most commonly associated cancers with celiac disease? |
|
Definition
1. enteropathy associated T-cell lymphoma - an aggressive lymphoma of intraepithelial T cells
2. Small intestinal anenocarcinoma- also more frequent in individuals with celiac disease |
|
|
Term
|
Definition
X-linked disorder characterized by severe persistent diarrhea and autoimmune disease that occurs most often in young children
Autoantibodies to enterocytes and goblet cells are common, and some patients may have antibodies to parietal or islet cells |
|
|
Term
| What are the 2 types of lactase deficiency |
|
Definition
1. congential: caused by a mutation in the gene encoding lactase, autosomal recessive disorder
2. acquired: caused by down-regulation of lactase gene expression, particularly common among native americans, african americans and chinese |
|
|
Term
|
Definition
rare autosomal recessive disease characterized by an inability to secrete triglyceride-rich lipoproteins. Caused by a mutation in microsomal triglyceride transfer protein (MTP). Causes failure of transepithelial transport.
Patients also have complete absence of all plasma lipoproteins containing apolipoprotein B |
|
|
Term
|
Definition
Geography: India, Africa
REservoir: Shellfish
Transmission: Fecal-oral, water
Epidemiology: sporadic, endemic, epidemic
Affected GI sites: Small intestine
Symptoms: severe watery diarrhea
Complications: dehydration, electrolyte imbalances |
|
|
