GI uWORLD, questions and answers. 100% PASS RATE, Graded A+

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GI uWORLD, questions and answers. 100% PASS RATE, Graded A+ Secretin is produced by ______________ in the duodenal mucosa in response to stimulation by intraluminal acidity. - ✔✔S cells __... ________________ are responsible for producing erythropoietin, a hormone that stimulates RBC production in the bone marrow. - ✔✔Renal peritubular cells ________________ increases partial cell acid production and therefore increases the amount of acid delivered from the stomach to the duodenum. - ✔✔Gastrin > Gastrin is the major hormone secreted by G cells of the gastric antrum. _____________________ viris infection is most commonly silent or subclinical ("anicteric") in young children but can also present as an acute, self-limited illness characterized by jaundice, malaise, fatigue, anorexia, nausea, vomiting, right upper-quadrant pain, or an aversion to smoking. - ✔✔Hepatitis A Acute hepatitis B infection is sometimes associated with a ______________ where hepatitis B surface antigen (HBsAg) is no longer present but anti-HBsAg is not yet detectable in serum. - ✔✔window period ____________________ is a common complication of abdominal and pelvic trauma. The pancreas is a retroperitoneal organ, and pancreatic injury is frequently a source of retroperitoneal bleeding. - ✔✔Retroperitoneal hematoma The spleen, liver, stomach, and transverse colon are ____________________ organs. Lacerations or rupture of these organs can occur in blunt abdominal trauma, but these injuries would lead to hemoperitoneum (free blood in the peritoneal space), not retroperitoneal hematoma. - ✔✔intraperitoneal Metabolism of 1 gram of protein or carbohydrates produce _____ calories of energy; Whereas, metabolism of 1 gram of fat produces _______ calories. - ✔✔4 ; 9 Ex. If a patient is instructed to consume 3000 cal per day and 30% of it protein. That means 900 of which are to be form protein. Because 1 g of protein yields 4 Cal of energy, this patient should consume (900/4 Cal) = 225 g/day of protein. The duodenal bash border enzyme ____________________ activates trypsin from its inactive precursor, trypsinogen. Trypsin degrades complex polypeptides to dipeptides, tripeptides, and amino acids while activating other pancreatic enzymes. __________________ deficiency impairs both protein and fat absorption, leading to diarrhea, failure to thrive, and hypoproteinemia. - ✔✔Enteropeptidase ; enteropeptidase _________________ of the stomach release the inactive form of pepsin, pepsinogen. Exposure to hydrochloric acid in the stomach activates pepsin, initiating protein digestion. - ✔✔Chief cells Staphylococcus aureus is capable of producing a highly heat-stable protein toxin called enterotoxin that cause staphylenterotoxemia, a syndrome characterized by nausea, vomiting and abdominal cramps following ingestion of __________________. - ✔✔preformed exotoxins > Subsequently, the food is allowed to sit at room temperature for an extended period of time (ig. at a picinic/pt luck), and S. aureus is able to mutely and produce exotoxin. > Poultry and egg products, meat and meat products, egg, tuna, chicken, potato and macaroni salads, cream-filled pastries, and mlid and diary products are the foods that are frequently incriminated in staphylococcal food poisoning. > The most frequently tested food item is a mayonnaise-containing food like potato or macaroni salad. > A similar clinical picture of rapid-onset nausea, vomiting, abdominal cramping and retching can be seen in food poisoning caused by Bacillus cereus which also contaminates food with a preformed heat-stable exotoxin. > B. cereus characteristically contaminates starchy foods such as rice (reheated fried rice) Failure of gut recanalization is a possible mechanism for development of _______________ - ✔✔duodenal atresia Around 6 weeks gestation, the midgut (supplied by the ______________________________ artery) herniates through the umbilical ring in order to grow rapidly. During this process, the midgut rotates 90 degrees counterclockwise. Following additional growth, the midgut returns to the abdominal cavity at 8-10 weeks gestation and turns an additional 180 degrees counterclockwise (270 degrees total). Subsequently, the gut is fixed to the posterior abdomen on a wide-based mesentery. - ✔✔superior mesenteric Failure of neural crest cell migration in the gut causes aganglionic sigmoid colon/rectum. The affect bowel segments cant relax and therefore narrow and obstructive. _____________________ presents in the neonatal period with delayed passage of meconium, abdominal dissension, and bilious emesis. - ✔✔Hirschsprung disease Intestinal malrotation results when the midgut undergoes incomplete embryological counterclockwise rotation. It can present as intestinal obstruction (due to compression by the adhesive bands) and ___________________ - ✔✔midgut volvulus (intestinal ischemia due to twisting around the blood vessels) > The twisting, referred to as a midgut volvulus, compromises intestinal perfusion and may lead to life-threatening bowel necrosis. The ____________________ supplies blood to the midgut, which spans form the third part of the duodenum to the proximal two-third of the transverse colon. - ✔✔superior mesenteric artery The hindgut encompasses the distal one-third of the transverse colon, the descending colon, the sigmoid colon, and the rectum. These structures receive their main arterial blood supply from the __________________ - ✔✔Inferior mesenteric artery The _____________ supplies blood to most foregut structures from the lower esophagus to the second part of the duodenum. Foregut derivatives include the liver, pancreas, and gallbladder. - ✔✔Celiac trunk > The celiac trunk also supplies the spleen. Crohn disease is associated with mutations in NOD2 (encodes an intracellular microbial receptor), resulting in decrease activity of NF-kB protein (a proinflammatory transcription factor) with reduced _______________. - ✔✔Cytokine production > This impairs the innate barrier function of the intestinal mucosa and allows intestinal microbes to induce an exaggerated response by the adaptive immune system, resulting in chronic gastrointestinal inflammation. Gastric parietal cells secrete *hydrochloric acid* (HCl) in response to 3 major stimulants: _____________, _________, and ____________ - ✔✔histamine, vagal output, gastrin > Histamine is realized from enterochromaffin-like (HCL) cells and binds to H2 receptors on the basolateral parietal cell membrane > Vagal stimulation causes *acetylcholine* release, which directly stimulates HCl secretion by binding to parietal cell muscarinic (M3) receptors. In addition, vagal stimulation indirectly promotes HCl secretion via gastrin-releasing peptide (GRP), which stimulate gastrin release from G cells. > G cells also release *gastrin* in response to protein-rich meals. Gastrin primarily stimulates HCl secretion by binding to the CCK-B receptor on HCL cells (promotes histamine release). It also directly binds to the CCK-B receptor on parietal cells, but this mechanism is less significant for acid secretion. __________________ block the final common pathway of gastric acid secretion from parietal cells, which is stimulated by *acetylcholine, histamine,* and *gastrin* - ✔✔Proton pump inhibitors (eg. omeprazole, lansoprazole) ________________ may promote peptic ulcer healing by binding to the base of mucosal ulcers and providing physical protection against gastric acid - ✔✔Sucralfate _________________ treats gastroesophagel reflux and peptic ulcer disease by blocking parietal cell H2 receptors. Although H2 receptor blockade would reduce gastric acid secretion in response to histamine or gastrin infusion. It would not significantly reduce acid secretion in response to vagal stimulation. - ✔✔Cimedtidine _________________ is a cholinomimeitc muscarinic agonist used to treat ileum and urinary retention. - ✔✔Bethanechol > It would promote gastric acid secretion by stimulating parental cell M3 receptors. Most duodenal peptic ulcers are caused by _________________________. - ✔✔H. pylori infection. > The most effective method to prevent disease recurrence is to eradicate the infection with antibiotic therapy (eg. amoxicillin plus clarithromycin) _____________________ should be avoided in patients with peptic ulcer disease as they can promote peptic ulcer formation, especially when combined with NSAIDs. - ✔✔Glucocorticoids Proton pump inhibitors suppress gastric acid secretion to a greater extent than histamine H2-recptor blockers (eg. _______________), allowing for superior ulcer healing during peptic ulcer disease. However, neither medication would prevent ulcer recurrence (which requires H pylori eradication) - ✔✔ranitidine ___________________ infection is a common cause of inflammatory gastroenteritis and can be acquired form domestic animals (cattle, chickens, dogs) or from contaminated food. The diarrhea is inflammatory and is accompanied by fever, abdominal pain and tenesmus. - ✔✔Camplyobacter > Campylobacter infection is associated with Guillain-Barre syndrome _______________________ is transmitted by consumption of contaminated shellfish. - ✔✔Vibrio parahemolyticus _______________________ services on steamed and fried rice where it produces a heat-stable enterotoxin - ✔✔Bacillus ________________ infection is commonly acquired by drinking contained water. A history of camping, hiking in the mountains and white-water rafting are classically associated with giardiasis. - ✔✔Giardia lamblia _______________________ infection beings following skin penetration by filariform (infectious) larva and can be diagnosed by finding rhabditiform (noninfectious) *larvae in the stool* - ✔✔Strongyloides stercoralis Trophozoites ard cysts are seen in the stool of patients with intestinal protozoal infection such as __________________ and ________________ - ✔✔Guardia lambia; Entamoeba histolytica __________________ migrate out of the anus at night to deposit eggs on the surrounding perianal folds. - ✔✔Enterobius vermicularis (pinworms) > Pinworm eggs are best detected by examining a piece of scotch tap applied to the perianal region shortly after awakening. Intestinal tapeworm ( eg. _______________, ______________, ______________) are flatworms made up of multiple segments called proglottids. These are shed from the still end of the worm and can be detected in the stool of infected individuals. - ✔✔Taenia solium, Taenia saginata, Diphyllobothrium latum Detection of parasite eggs in the stool is used to diagnose _________________ - ✔✔Schistosomiasis > Caused by Schistosoma mansion or S japonica. ____________________ is an opioid anti-diarrheal drug that binds to *mu opiate receptors* in the GI tract and *slows motility*. Overuse can lead to euphoria and physical dependence. To discourage abuse, diphenoxylate is combined with atropine, which induces adverse effects if taken in high doses. - ✔✔Diphenoxylate Secretary diarrhea can be due to many different substances (eg. vasoactive intestinal peptide, bacterial toxins) that increase secretions. Agents that target secretory diarrhea include _________________, ___________ and possibly some probiotic preparations. - ✔✔Bismuth subsalicylate, octreotide The ____________ and ______________ lies between regions of perfusion of major arteries. These "watershed" areas are susceptible to ischemic damage during hypotensive states, especially in patients with underlying arterial insufficiency. - ✔✔splenic flexure; rectosigmoid junction These "Watershed" ares are primarily in the left colon at the *splenic flexure* (border between SMA and IMA supply) and *rectosigmoid junction* (border between sigmoid artery and superior rectal artery*. __________________ is an oxidase-costive, gram-negative, comma-shaped organism able to grow on high-alkaline selective media (Eg. thiosulfate-citrate-bile salt-sucrose agar). - ✔✔Vibrio cholerae > Cholera is acquired through contaminated food or water ingestion. Cases can be isolated or present in small outbreaks. > Fluid replacement is the mainstay of management. _________________ is an S-shaped, motile, gram-negative, oxidase positive rod), a very common cause of diarrhea worldwide - ✔✔Campylobacter jejuni _____________________ in the stool are sometimes seen in intestinal parasitic infections. Diarrhea with *peripheral* eosinophils can be seen with Strongyloide, Ancylostoma, Ascaris, Toxocara, and Trichinella (but not with Giardia or Entamoeba) - ✔✔Charcot-Leyden crystals The presence of leukocytes with monocytic predominance is typical for typhoid fever caused by ____________________ - ✔✔Salmonella Typhi The presence of leukocytes with neutrophilic predominance would be typical of invading bacteria that cause dysentery or inflammatory diarrhea (eg. ____________, __________, __________, and _________) - ✔✔Shilled species Salmonella species C. jejuni EIEC _______________________ syndrome occurs when the transverse portion of the duodenum is entrapped between the SMA and aorta, causing symptoms of partial intestinal obstruction. This syndrome occurs when the artomesenteric angle critically decreases, secondary to diminished mesenteric fat, pronounced lordosis, or surgical correction of scoliosis. - ✔✔Superior mesenteric artery *Bilious emesis* in a neonate is a sign of intestinal _______________ the second part of the duodenum. The differential diagnosis includes: midgut volvulus, which is a surgical emergency and must be excluded definitively. Other causes include *intestinal stenosis* and *atresia*. The most distal the atresia, the more likely it is to present with abdominal distention rather than billows emits. The absence of a segment of jejune and ileum in this case confirmed that the infant's condition is due to intestinal atresia. - ✔✔Obstruction below Intestinal atresia distal to the duodenum occurs due to _________________ in utero. - ✔✔vascular accidents In patients with hepatic encephalopathy, lowering the blood ammonia levels is typically accomplished with real administration of a disaccharide (eg. ________________). - ✔✔lactulose > Bacterial action on lactulose results in acidification of colonic contents, which then coverts absorbable ammonia into nonabsorable ammonium ions, trapping it in the stool and thereby increasing fecal nitrogen excretion. ______________________ refers to a reversible decline in neurologic function that occurs due to failure of the liver to metabolize waste products such as ammonia. Ammonia is normally produced by the GI tract as a result of enterocytic catabolism of glutamine and colonic bacterial catabolism of dietary protein. GI bleeding causes *increased nitrogen delivery* to the gut in the form of hemoglobin, which is then converted into ammonia and absorbed into the bloodstream. The ammonia then enters the liver through the portal vein and is detoxified to urea. - ✔✔Hepatic encephalopathy ___________ activity of GABA neurotransmitter system is thought to be responsible for the altered mental status seen in hepatic encephalopathy. - ✔✔Increased (not decreased) In chronic liver failure, hepatocytes dysfunction and the shunting of blood through portosystemic collaterals impair the liver's detoxification ability. This leads to _________________ and other neurotoxins in the circulation, causing altered *amino acid transport across the blood-brain barrier, impaired neurotransmitter metabolism, and depressed cerebral glucose metabolism. - ✔✔accumulation of ammonia The *portal triad* runs through the hepatoduodenal ligament and is composed of the _______________, __________, and _____________. In the setting of traumatic liver injury with persistent bleeding, occlusion of the hepatoducodenal ligament can be performed to identify the vascular source (i.e.. the Pringle maneuver). If liver bleeding does not cease when the portal triad is occluded, it is likely there has been injury to the the __________________ or ___________ - ✔✔> Hepatic artery, portal vien, and common billed duct > Inferior vena cava, hepatic veins Occlusion of the portal triad (Pringle maneuver) is a surgical technique used to distinguish the source of ___________________. If hepatic bleeding persist after occlusion of the portal triad, the *inferior vena cava* or *hepatic veins* are likely to be injured. - ✔✔right upper quadrant bleeding The _____________ part of the duodenum courses horizontally across the abdominal aorta and inferior vena cava at the level of the third lumbar cerebra. The superior mesenteric vessels lie anterior to the duodenum at this location. - ✔✔third Celiac disease (gluten-sensitive enteropathy) classically presents between 6-24 months wth abdominal pain, diarrhea, vomiting, and weight loss. Duodenal biopsy revels _________, ________, and ______________. Treatment with gluten-free diet resolves symptoms and normalizes serology and histology. - ✔✔crypt hyperplasia, villous atrophy; intraepithelial lymphocyte infiltration. ____________________ is characterized by the abnormal proliferation of mast cells and increased histamine release. Histamine causes hyper secretion of gastric acid by parietal cells in the stomach as well as variety of other symptoms (eg. hypotension, flushing, pruritus) - ✔✔Systemic mastocytosis > In systemic mastocytosis, clonal mast cell proliferation occurs in the bone marrow, skin and other organs. > Mast cell proliferation often is associated with mutations in the *KIT* receptor tyrosine kinase. Pancreatic endocrine tumors may secrete _________ (Zollinger-Ellsion syndrome), _________ (hypoglycemia), _______________ (hyperglycemia, rash) _________________ (diarrhea, cholelithiasis, hyperglycemia), or ___________________ (watery diarrhea, hypokalemia, achlorhydria) - ✔✔Gastrin - Zollinger-Ellsion snydrome Insulin - Hypoglycemia Glucagon - Hyperglycemia, rash Somatosatin - diarrhea, cholelithiasis, hyperglycemia Vasoactive Intestinal peptide - watery diarrhea, hypokalemia, achlorhydria Meckel's diverticulum often also contain ______________, which may cause ulceration of the adjacent mucosa and lower GI bleeding (melena/hematochezia). Meckel's diverticulum is a true diverticulum and consists of all parts of the intestinal wall (Mucosa, submucosa, and muscular layers) - ✔✔acid-secreting ectopic gastric tissue Intrinsic factor (IF) is a glycoprotein that is normally secreted by parietal cells in the stomach and is necessary for the absorption of vitamin B12 in the (terminal) ileum. Patients who have undergone a total gastrectomy requires lifelong _______________________ due to inability to produce IF. - ✔✔Vitamin B12 supplementation (a water-soluble vitamin) Abnormal spasm or diminished relaxation of the cricopharyngeal muscles during swallowing ( _____________________) is thought to be the underlying mechanism of Zenker diverticulum formation. - ✔✔cricopharyngeal motor dysfunction > Diminished relaxation of the criopharyngela muscles during swallowing results in increased intraluminal pressure in the oropharynx. This may eventually cause the mucosa to herniate through a zone of muscle weakness in the posterior hypopharnyx, forming a Zenker (False) diverticulum, which presents in *elderly* patients with oropharyngeal dysphagia, halitosis, regurgitation, and recurrent aspirations. Mucosal tears around the gastroesophageal junction can be caused by ______________ in the stomach during prolonged or recurrent retching/vomiting (Mallory-Weiss syndrome) - ✔✔increased intraluminal pressure _______________ usually involves the skin and GI tract and is common in HIV patients not on antiretroviral therapy. Endoscopy reveals characteristic lesions, which range from reddish/violet flat maculopapular lesions to raised hemorrhagic nodules or polypoid masses. Biopsy can show spindle cells, neovascularization, and extravasated red blood cells. - ✔✔Kaposi's sarcoma _________________________ is a serum tumor marker that is often moderately elevated in patients with chronic viral hepatitis. However, it can be strikingly elevated in those with hepatocellular carcinoma, and a sudden rise can be a sign that a patient with chronic liver disease is harboring hepatocellular carcinoma. - ✔✔Alpha-fetoprotein This patient has sharp pain and bright red rectal bleeding on defection, suggesting an ________________. - ✔✔Anal fissure > The majority of fissures, especially those causing prolonged symptoms, occur at the *posterior midline* of the anal verge. This is likely due to the relatively poor perfusion of the posterior anal canal, which makes it muscoa sensitive to trauma and slow healing times. Most fissure are related to *chronic constipation*, with high anal pressures and passage of hard stools. This patient, an older woman with intermittent abdominal pain and a cholesterol-containing mass lodge at the ileocecal value, has a ________________. - ✔✔Gallstone ileus > Gallstone ileus is a mechanical bowel obstruction caused when a large gallstone erodes into the intestinal lumen. Gallstone ileus is a mechanical bowel obstruction caused when a large gallstone erodes into the intestinal lumen. ____________________ is a common finding. - ✔✔Pneumobilia (air in the biliary tract) In ________________, there is occlusion of the hepatic vein, which drains blood from the liver and portal circulation into the systemic circulation. Liver biopsy shows centrilobular congestion and fibrosis. - ✔✔Budd-Chiari syndrome Portal vein thrombosis causes _____________, __________, and ________________. It does not cause histologic changes to the hepatic parenchyma. Ascites is uncommon as the obstruction is presinusoidal. - ✔✔portal hypertension, splenomegaly, varicosities at portocaval anastomoses. Patient with Crohn disease affecting the _____________ (most common site of involvement) are prone to developing gallstones. Decreased bile acid reabsorption by the inflamed _______________ promotes cholesterol supersaturation of the bile, resulting in gallstone formation. - ✔✔terminal ileum; terminal ileum ____________________ is a tumor necrosis factor-alpha inhibitor used to treat severe or refractory Crohn disease; it is associated with an increased risk of serious infections. - ✔✔Infliximab _____________________ is an autosomal recessive disease characterized by abnormally high iron gastrointestinal absorption that causes an iron overload, primarily in parenchymal organs such as the heart, pancreas, and liver. - ✔✔Hemochromatosis > Common clinical manifestations of hemochromatosis include liver disease with hepatomegaly, abdominal pain, skin hyper pigmentation (particularly in sun-exposed area)S, diabetes mellitus secondary to pancreatic islet destruction, impotence, arthropathy, and cardiac dysfunction and enlargement. Late-stage ________________ can be characterized by "bronze diabetes", the triad of skin hyper pigmentation, diabetes mellitus, and pigment cirrhosis with hepatomegaly. - ✔✔hemochromatosis Wilson's disease is the likely diagnosis in a patient younger than 30 years old with unexplained chronic hepatitis. The presence of ________________ and increased ____________ or _____________ provides diagnostic confirmation. - ✔✔low serum ceruloplasimin Increased urinary copy excretion Kayser-Fleischer rings Gastric varies are dilated submucosal veins that can cause life-threatening bleeding in the upper GI tract. The varies are commonly due to portal hypertension, which can be a complication of cirrhosis. Gastric varies can also be seen with _________________ due to chronic pancreatitis, pancreatic cancer, and abdominal tumors. - ✔✔Splenic vein thrombosis > Splenic vein thrombosis can increase pressure in the short gastric veins and cause *gastric varices* only in the *fundus*. The rest of the stomach and esophagus are usually not affected. __________________ improves cholesterol solubility by reducing the mount of cholesterol secreted into the bile and increase binary bile acid concentration. Normally, bile acid and phospholipids soluble the cholesterol to prevent stone formation. Decrease amounts of bile acids and phospholipids can cause the bile to become supersaturated with cholesterol, allowing it to crystallize and form cholesterol gallstones. - ✔✔Bile acid supplementation Fibrates ___________ cholesterol content in bile, which increases the risk of gallstones. - ✔✔increases The ________ and _________ phases stimulate gastric acid secretion, while __________ influences tend to reduce gastric acid secretion. - ✔✔cephalic ; gastric; intestinal NK cells recognize and kill cells with _____________ MHC I antigen cell surface expression, such as virus-infected cells and tumor cells. They are large lymphocytes that contain performs and granzymes in cytoplasmic granules. NK cells kill target cells by inducing apoptosis. - ✔✔decreased Compared to Salmonella that can cause gastroenteritis, ___________________ has a low infectious dose (ID50) and can cause infection with low amounts of the organism. - ✔✔Shigella > Depending on the age and condition of the host and on the species of Shigella, as few as 10 Shigella organism can cause disease. > A much large inoculum of Salmonella (approx 10^7) is required for successful infection in a susceptible host. In MHC _____, it is associated with acidification of lysosomes. - ✔✔II MHC Class II is used to present antigen that antigen presenting cells (dendrite cells, macrophages, and B-lymphocytes) have encountered in the body and have taken up by phagocytes or endocytosis. Amatoxins are found in a variety of poisonous mushrooms (eg. Amanita phalloides, known as death caps) and are potent inhibitors of _____________________ - ✔✔RNA polyermase Ii (halting mRNA synthesis) Acyclovir and released drugs (eg. famciclovir and valacyclovir) are inhibitors of ____________ - ✔✔viral DNA polymerase. In hyperammonemia (such as in advance liver failure due to cirrhosis), ammonia can cross the blood-brain barrier and causes excess _________________ to accumulate within astrocytes. - ✔✔Glutamine >When *excess ammonia* is present in the blood, it corps the BBB and is taken up by astrocytes, *increasing glutamine production* The presence of excess glutamine within astrocytes leads to increased intracellular osmolarity, Hyperammonemia consequently decrease the tmaount go glutamine available for conversion to glutamine in neurons, resulting in *disruption of excitatory neurotransmission* Alanine is an amino group transporter in the _______________ in liver and muscle tissue. This process allows tissues that use amino acids for fuel - ✔✔glucose-alanine cycle _________________ functions are key intermediate in the TCA cycle and as a nitrogen transport in metabolic reaction. - ✔✔alpha-ketoglutrate Ulcerative colitis has the following unique characteristics that operates its from Crohn's disease (under the inflammatory bowel disease category) 1. 2. 3. 4. - ✔✔1) The rectum is always involve,d involvement of other areas of the intestine is variable 2) Inflammation is limited to the [Show More]

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