GI Flashcards
(85 cards)
1
Q
Achalasia
A
- Disordered esophageal motility and inability to relax LES
- due to damaged inhibitory ganglion cells of the myenteric plexus
- **“birds beak” sign on barium swallow study
2
Q
Giardia
A
Sx: diarrhea, flatulence, foul smelling stools, abd cramping, malabsorption
HPI: hiking and drinking contaminated water, most common enteric parasite in US and Canada
Histo: stool sample reveals elippsoidal cysts smooth well defined walls and 2+ nuclei
-infects duodenal and jejunal mucosal lining
Tx: metrobendizole
3
Q
Pernicious anemia
A
Ab CD4 mediated destruction of parietal cells in gastric fundus and body (parietal cells secrete IF necessary for the absorption of B12 in ileum)
–> megaloblastic anemia , affects upper glandular layer (oxyntic)
Sx: fatigue and lower extremity paresthesias , elevated pH, increased secretion of gastrin
Chief cells found in lower glandular layer (pepsinogen); parietal cells secrete IF and HCl
4
Q
Hirschprung disease
A
- Abnormal migration of neural crest cells during embryogenesis (move caudally along vagus nerve)
- neural crest cells give rise to ganglion cells (parasympathetic) make submucosal and myenteric plexuses –> responsible for peristalsis
- sx: affected segment becomes narrowed bc it can’t relax (always involves rectum and anus)
- can lead to megacolon
5
Q
Celiac disease
A
Histo: villous atrophy, crypt hyperplasia, lymphocytic inflitration in duodenum and proximal jejunum
- chronic malabsorptive disorder caused by hypersensitivity to gluten (found in wheat, barely and rye)–> gliadin triggers autoimmune mediated rxn
- presents brown ages of 6-24 months with the introduction of gluten into diet
- elevated IgA and anti transglutaminase Ab
- tx: gluten free diet
6
Q
Polyethylene glycol
A
Osmotic laxative used to tx constipation (non absorbable and pulls water into lumen osmotically)
Magnesium hydroxide is another osmotic laxative often used
7
Q
Zollinger-Ellison syndrome
A
- Gastrin secreting tumor
- Gastrin hypersecretion induces parietal cell hyperplasia (increased HCl), enlargement of gastric folds
- excess acid causes peptic ulcer disease, heartburn and diarrhea
8
Q
Secretin
A
- produced by S cells in the small intestine
- increases bicarb production by the pancreas and watery, alkaline pancreatic juice
- inhibits gastric acid secretions and stimulates pyloric sphincter contraction
9
Q
Kehr sign
A
Any abdominal process irritating the phrenic nerve sensory fibers around the diaphragm can cause referred pain to the C3-C5 shoulder region
-phrenic nerve irritation can also cause hiccups
-phrenic nerve originates from C3-C5 and provides motor function to the diphragm
10
Q
Extra intestinal manifestations of Crohns disease
A
Ankylosing spondylitis and peripheral arthritis which manifest as low back pain and joint stiffness that is worst at night
11
Q
Mallory-Weiss tear
A
Upper GI mucosal tear near GEJ; caused by forceful vomiting through tight LES (retching or vomiting)
- repetitive omitting leads to metabolic alkalosis due to loss of gastric acids
- commonly occurs among alcoholics
12
Q
Acute pancreatitis due to EtOH abuse
A
> 2 AST:ALT ratio and absence of gallstones
- chronic pancreatitis: macrocytosis is seen due to poor nutrition (i.e. Folate deficiency)
- after gallstones, 2nd most common cause of acute pancreatitis
13
Q
Hepatoduodenal ligament
A
Surrounds the portal triad (hepatic artery, portal vein and common bile duct)
- occlusion of the hepatoduodenal ligament called “the Pringles maneuver”
- technique used to distinguish RUQ bleed; if bleeding doesn’t stop w Pringle maneuver then bleeding is from IVC or hepatic veins
14
Q
Urease test
A
- used in the Dx of H. Pylori infection
- h. Pylori secretes ureases which convert urea to carbon dioxide and ammonia, causing a pH increase and color change of the phenol red pH indicator indicating alkalinization of the solution
15
Q
NK cells
A
Recognize and kill cells w decreased or absent MHC class 1 antigen cell surface expression, such as virus-infected cells and tumor cells ; kill target cells by inducing apoptosis
- don’t express CD4, CD8 or CD3
- don’t require maturation in the thymus
- don’t require antigen activation
16
Q
CCK
A
- hormone responsible for gallbladder contraction
- produced by cells of duodenum and jejunum when fat protein rich chyme enters the duodenum
- increases pancreatic enzyme secretion and decreases gastric emptying
- risk factors for gallbladder disease: forty, fat and female
17
Q
Secretin
A
Promotes bicarb secretion from pancreas
18
Q
Base excision repair
A
-used to correct single-base DNA defects
Order:
-glycoylases remove defective base
-sugar-phosphate site cleaved and removed by endonucleases and lyase
-DNA polymerase replaces missing nucleotide
-Ligase seals reminding nick
***nitrates promote deamination of cytosine, adenine and guanine
19
Q
Mu opioid analgesics and RUQ abdominal pain
A
Can cause contraction of smooth muscle cells in sphincter of oddi leading to spasm and increase in in common bile duct pressures
-use NSAID instead
I.e. Morphine
20
Q
Porcelain gallbladder
A
- late complication of chronic cholecyctitis assoc w cholelethiasis (gallstones)
- CT: palpable mass that include thickened gallbladder wall and rim of patchy or uniform calcification
- increased risk for adenocarcinoma of the gallbladder
21
Q
HIV associated esophagitis
A
3 most common causes:
- Candida ( patches of grey white pseudomembrane on erythematous mucosa)**most common
- CMV (linear ulcerations); inclusion bodies; CMA esophagitis also occurs in transplant recipients
- HSV-1 (small vesicles-> punched out ulcers); cowdry bodies
All present as dysphasia and/or odynophagia
22
Q
Intestinal atresias
A
Duodenal: failure of recanalization at 8-10 weeks gestation; bilious or non bilious emesis, “double bubble” sign on x ray; assoc w Down syndrome
Jejunum/ileum: vascular injury; bilious emesis, abdominal distention; associated w gastroschisis
Colonic: Unknown; constipation, abdominal distention; assoc w Hirschprungs disease
“Apple peel” atresias occur when the SMA is occluded
23
Q
Lead poisoning in adults
A
Risk factors: occupational exposure (lead paint, batteries, ammunition, construction)
Clinical features: GI (constipation), neurological (peripheral neuropathy), hematologic (anemia), bluish pigmentation at the gum-tooth line
Lab findings: microcytic anemia, elevated venous lead levels, basophilic stippling on peripheral smear; normal iron studies
-lead inhibits the heme synthesis pathway
24
Q
Howell Jewel bodies
A
Nuclear DNA remnants inclusions in peripheral RBCs that are normally removed by the spleen during circulation. Presence indicates decreased or absent spleen function (i.e. Post splenectomy)
25
Systemic mastocytosis
Clonal mast cell proliferation in bone marrow, skin and other organs.
Assoc w mutation in KIT receptor TK
Excessive histamine release from degranulation of mast cells leads to syncope, flushing, hypotenison, pruritis and urticaria
Histamine also induces gastric acid secretion via parietal cells causing diarrhea
Histamine: vasodilation and fall in BP, gastric acid release, itching
26
Meckel diverticulum
Failed obliteration of vitelline (omphalomesenteric) duct
Sx: painless lower GI bleed
Ectopic gastric mucosa secretes acid via parietal cells
Tc-pertechnetate binds parietal cells
True diverticulum; transmural
27
Diverticulosis
Hematochezia w abnormal outpouchings from colonic epithemlium
Pathogenesis involves pulsion, increased intraluminal pressure during strained bowel movements
Only mucosa and submucosa herniate through weakness in muscularis
Most commonly in sigmoid colon
28
Right sided vs left sided colon cancer
Right sided (ascending colon)
- grow as large bulky masses that protrude into colonic lumen, more likely to bleed and cause iron def anemia, don't develop intestinal obstruction bc right colon is larger and stool is more liquid
- Sx: anorexia, malaise, unintentional weight loss
```
Left sided (rectosigmoid colon)
-smaller, infiltrate wall if the colon narrowing the lumen causin obstruction,
```
Lung and liver are common sites of metastasis
Most common GI malignancy
29
Most common causes of acute pancreatitis
Gallstones and alcoholism
30
Tx of Hep C
Interferon alpha and ribavirin
Ribavirin: interferes w duplication of viral genetic material, lethal hypermutation, inhibiting RNA polymerase, defective 5'cap formation
31
Abetalipoproteinemia
Autosomal recessive, loss of function mutation in MTP gene
Impaired formation of apolipoprotein B containing lipoproteins (i.e. Chylomicrons and VLDL)
Sx: accumulation of lipids in the absorptive cells of the intestinal epithelium; enterocytes contain clear or foamy cytoplasm
Malabsorption of fat
32
Villous adenoma
Mass w long glands and villi-like projections in colon
Large sessile and can have a velvety or cauliflower like projections
Most likely to go malignant transformation
Secrete large quantities of watery mucus, leading to secretory diarrhea, hypovolemia and electrolyte imbalance
33
Indirect vs direct inguinal hernias
Indirect:
- more common
- failure of processus vaginalis to obliterate, allowing contents to protrude through deep inguinal ring
- above epigastric vessels and inguinal ligament
- may descend into scrotum via inguinal canal and out ext inguinal ring
Direct:
- Protrude through Hasselbachs triangle, weak spot on ant abd wall
- rectus abdominus muscle medially, inferior epigastric vessels laterally and inguinal ligament inferiorly
34
Chronic pancreatitis presentation
Epigastric pain and pancreatic exocrine insufficiency resulting in fat malabsorption/ steatorrhea
35
Inhaled anesthetic hepatotoxicity
Assoc w highly lethal fulminant hepatitis that cannot be distinguished from viral hepatitis. Patients have significantly elevated aminotransferase (AST) levels due to massive hepatocellular injury and a prolonged PT time due to failure of hepatic synthetic function
I.e. Halothane
36
Tx of nasuea (Antiemetic)
5-HT3 receptor antagonist for tx of visceral nausea due to GI (i.e. Odansetron)
Anti histamines and anti cholinergics for vestibular nausea, motion sickness and vertigo
Dopamine antagonist for nasuea w migraines
All hit area posterma in medulla which controls nausea and vomitting
37
Small intestinal bacterial overgrowth
Often assoc with gastric bypass surgery resulting in the overproduction of Vit K and folate (bacterial synthesis) assoc w nausea, vomiting, bloating, abd discomfort and malabsorption
--> results in def of most other vitamins and zinc
Excessive bacterial proliferation in blind ended gastroduodenal segment that is anastamosed to jejunum dismally
38
Diagnostic test for Celiac
Duodenal biopsy
39
Small bowel syndrome
Malabsorptive condition that typically occurs in patients with massive bowel resection or Crohns disease
-loss of absorptive surface, decrease in transit time leading to post prandial voluminous diarrhea and weight loss due to malabsorption of nutrients
40
Presentation of appendicitis
- dull visceral pain at the umbilicus due to afferent nerve fibers entering spinal cord at T10
- progressive inflammation irritates parietal peritoneum and abd wall to cause more sever somatic pain shifting to McBurney point
Visceral pain is dull and non localized (luminal distention and stretching of smooth muscle
Somatic pain is severe and well-localized
41
Most common malignant hepatic lesion
Metastasis from another primary site (breast, lung, colon), not hepatocellular carcinoma
-CT shows multiple hypodense masses in the liver--> may result in hepatomegaly
42
Colorectal carcinoma in pts with IBD
- long standing ulcerative colitis is assoc w increased risk of colorectal cancer
- duration and extent are he most significant risk factors
- compared to sporadic cases of CRC, colitis assoc CRC affect younger pts, progress from flat and non-polypoid dysplasia, appear mutinous and/or have signet ring morphology, develop p53 mutation early and APC mutations late (opposite), multifocal in nature
43
Trypsin
Trypsinogen is activated by enterokinase in the duodenum to trypsin. Trypsin then activates all other enzymes in the duodenum from the pancreas; can also activate other trypsinogen molecules
- SPINK 1 is a trypsin inhibitor, trypsin can also serve as its own inactivator
- main activator of pancreatic digestive proenzymes
44
Supplementation for breastfed infants
Vitamin D
- risk factors: exclusively breastfeeding, lack of sunlight exposure, dark skin pigmentation
- prevent rickets
Iron
-risk factors: pre term/ low birth weight
***vit K injection supplementation at birth to prevent hemorrhagic disease
45
Statins
1st line therapy for hypercholestrolemia; competitively inhibit HMG CoA reductase (rate limiting step in hepatic cholesterol synthesis)
-causes increased uptake of LDL from circulation
Bile acid binding resins bind bile acids in the GI tract, resulting in synthesis of more bile salts therefore consuming more cholesterol stores; but decreased hepatic cholesterol is a activating factor for HMG CoA reductase and results in increased hepatic cholesterol synthesis; block w a statin
46
Kaposi's Sarcoma
Usually involves the skin and GI tract and is common is HIV patients not on antiretroviral therapy
Endoscopy: redish/violet flat maculopapular lesions to raised hemorrhagic nodules or polyploid masses
Biopsy: spindle cells, neovascularization, and extravasated RBCs
HHV-8
47
Location of esophagus
Located btwn the trachea and vertebral body in superior thorax; typically collapsed and w no visible lumen on CT
48
2 types of gastric adenocarcinomas
Intestinal
- well formed glands
- grow as modular, polypoid, and well demarcated masses that rapidly expand
- lesions ulcerated and bleed
Diffuse
- don't form glands
- signet ring carcinomas (cell w abundant mucin droplet that pushes the nucleus to one side)
- diffuse involvement due to loss of E-Cadherin protein
- cause "leather bottle stomach"- Linitis plastica
49
Dublin Johnson Syndrome
Benign autosomal recessive disorder w defective hepatic excretion of conj bilirubin due to mutation in canalicular membrane transport protein
Direct (conjugated) hyperbilirubinemia
Liver may appear black due to impaired excretion of epi metabolites that accumulate within lysosomes
50
3rd part of the duodenum
Courses horizontally across the abd aorta and IVC at the level of the 3rd lumbar vertebra
Superior mesenteric vessels lie anterior to the duodenum
51
Hyperestrinism in liver cirrhosis
Arises likely due to increases in androstenedione production, androgen aromatization, and SHBG (preferentially binds testosterone). Impaired estrogen metabolism by the liver may also contribute.
Sx: gynecomastia, testicular atrophy, decreased body hair and spider angiomata
52
Most common intra abdominal organ injured during blunt trauma
Spleen
- mesodermal origin (the dorsal mesentery)
- although it is supplied by the splenic artery (branch of major foregut vessel, the celiac trunk), it is not foregut derived
53
Acute viral hepatitis A presentation
Histo: "spotty necrosis" w ballooning degeneration (hepatocyte swelling), Councilman bodies (eosinophilic apoptotic hepatocytes) and mononuclear cell infiltrates
Sx: fever, malaise, anorexia, nausea/vomitting, and RUQ pain.
After 1 week signs of cholestasis such as jaundice, pruritis, dark colored urine (due to increased conj bilirubin) and acholic stools (lacks bilirubin pigment)
54
Groin hernias
Indirect inguinal
- male infants
- patent process vaginalis, contents protrude through deep inguinal ring, travels lateral to the inferior epigastric vessel
Direct inguinal
- older men
- weakness of transversalis fascia, contents protrude through Hesselbachs triangle, travels medial to epigastric vessels, protrude through external inguinal ring and are covered by spermatic fascia
Femoral
-woman
Weakness of proximal femoral canal, contents protrude through femoral ring, travels inferior to inguinal ligament
55
Gallbladder
Functions to actively absorb water from bile. Gallbladder hypomotility causes bile concentration, which promotes precipitation and accumulation of viscous billiary sludge that predisposes to gallstone formation and bile duct obstruction
Risk factors: pregnancy, rapid weight loss, high spinal cord injures, prolonged use of total parenteral nutrition or octeotride
56
Portacaval anastomoses
Esophageal varices, left gastric vein, esophageal vein
Hemorrhoids, superior rectal vein, middle and inferior rectal veins
Caput medusa, paraumbilical veins, superficial and inferior epigastric veins
57
Vit A deficiency
Night blindness and hyperkeratosis (coarse and dry)
58
Adenoma to carcinoma sequence
1) mutation in APC tumor suppressor gene-increased risk for polyp
2) K-RAS (polyp formation)
3) p53 (carcinoma)
59
Ectopy
Microscopically and functionally normal cells/tissue found in abnormal location due to abnormal embryonic maladaption
I.e. Meckels diverticulum with pancreatic cells
Vs Metaplasia: replacement of one type of epithelium with another not typical for location; occurs during adult life and is initially a compensatory process
60
Cavernous hemangioma
Most common benign tumor of the liver
Cavernous, blood filled spaces of variable some lined by single epithelial layer
Biopsy not recommend as can cause fatal hemorrhage
61
Retroperitoneal abdominal organs
SAD PUCKER
Suprarenal (adrenal glands)
Aorta and IVC
Duodenum except 1st part
```
Pancreas head and body
Ureters and bladder
Colon (ascending and descending)
Kidneys
Esophagus
Rectum
```
62
Sudan III stain
Qualitative assay of stool that can easily ID unabsorbed fat and confirm malabsorption
Fats are typically the earliest and most severely affected nutrient during in generalized malabsorption
63
Shigella
Infectious GI disease most commonly caused by S sonnei
Invades GI mucosa by gaining access to microfold (M) cells in ileal Peyers patches through endocytosis
Sx: diarrhea w blood and mucus
64
Pseudoemembranes
White/yellow plaques with fibrin on colonic mucosa
Assoc w C.diff
65
Rifaximin
Non absorbable antibiotic that alters the GI flora to decrease intestinal production and absorption of ammonia (from nitrogen products)
GI bleed ->catabolism of Hb increases nitrogen products ->nitrogen converted to ammonia by gut
Excess dietary protein -> increases ammonia
Lactulose increases conversion of ammonia to ammonium
66
Gastric erosions vs ulcers
Erosions are mucosal defects that do not fully extend through the muscularis mucosa (only mucosal layer)
Ulcers penetrate through the mucosal layer and into the submucosa
67
Odynophagia
New onset usually indicates the progression to erosive esophagitis and the formation of an ulcer in the setting of chronic GERD
68
Breast milk jaundice
Hyperbilirubinemia that peaks at 2 weeks
Beta-glucuronidase in breast milk deconjugates bilirubin -> increased absorption and enterohepatic circulation of bilirubin
69
Arsenic poisoning
Binds to sulfhydryl groups and disrupts cellular respiration and gluconeogenesis
Sources: pesticide, contaminated water from wells, pressure treated wood
Manifestations: garlic breath, vomitting, watery diarrhea, QTc prolongation
Tx: dimercaprol (cheating agent that increases urinary excretion of heavy metals by forming non toxic soluble chelates
70
Gastroduodenal artery
Supplies the pylorus, proximal part of the duodenum and indirectly the pancreatic head (ant and post superior pancreaticoduodenal arteries)
71
Tracheoesophageal fistula with esophageal atresia
Failure of the primitive foregut to appropriately divide into separate trachea and esophageal structures
Sx: infant with excessive secretions and choking/cyanosis during feeding
Dx: inability to pass NG tube into stomach
72
Gallstone ileus
Complication of long withstanding cholelethiasis in elderly women
Gallstone causes a cholecysternic fistula btwn the gallbladder and the gut
Gallstone passes to intestine and creates a small bowel obstruction (high pitched bowel sounds)
Gas may enter biliary tree
73
Acute appendicitis
Obstruction of the lumen of the appendix
Fecaliths, hyperplastic lymphoid follicles, foreign bodies or tumors may cause obstruction
RLQ pain, nausea, vomiting, diarrhea, and fevers are typical
Starts as peri umbilical pain and moves to RLQ
74
Splenic vein thrombosis
Pancreatic inflammation (pancreatitis, pancreatic cancer) can cause a blood clot within the splenic vein, which can increase pressure in the short gastric veins and lead to gastric varies only in the fundus
75
Toxic megacolon
Complication of ulcerative colitis
Pts typically present with abdominal pain/distention, bloody diarrhea, fever and signs of shock (hypotension and tachycardia)
Plain abdominal X-ray (colonic dilation w multiple air-fluid levels
76
Uncomplicated umbilical hernia
Defect at the linea alba covered by skin-incomplete closure of the umbilical ring
Reducible bulge at umbilicus, notably with increased abdominal pressure (crying, passing bowel movements)
Assoc w Down syndrome, hypothyroidism, beckwith-wiedmann syndrome
77
H. Pylori
Noninvasive found attached to the gastric mucosa
Produce urease which converts urea to ammonia alkalinizing the surround pH which allows the bacteria to survive
Antral gastritis: Chronic inflammation leads to decreased somatostatin, increased gastrin, increased parietal cells, increased acid which leads duodenal ulcers
High prevalence in individuals from China
Tx: triple therapy (amoxicillin, clarithromycin, PPI)
78
Necrotizing enterocolitis
```
Common GI emergency affecting newborns
Bacterial invasion (immunological immaturity) and ischemic necrosis of bowel wall, assoc w prematurity and initiation of enteral feeding
Abdominal X-ray shows pneumoatosis intestinalis (air in the bowel wall) confirms Dx -> thin curvilinear areas of lucency
Bowel becomes congested and gangrenous with the formation of intramural gas collections
```
79
Blood supply of stomach
Proximal lesser curvature: celiac -> L gastric
Distal lesser curvature: celiac-> common hepatic -> proper hepatic-> R gastric
Proximal greater curvature: celiac-> splenic-> L gastroepiploic
Distal greater curvature: celiac-> common hepatic-> gastroduodenal-> R gastroepiploic
Proximal greater curvature above splenic artery: celiac-> splenic-> short gastric arteries
80
Stress-related mucosal disease
Acute gastric mucosal defects that develop in response to severe physiologic stress (eg. Shock, extensive burns, sepsis, severe trauma, intracranial injury). Multiple small, circular lesions in the stomach, ranging from superficial erosions to full thickness ulcers. Ulcers may bleed.
Usually caused by local ischemia
Curlings ulcers (ulcers in proximal duodenum assoc. w severe trauma/burns) and Cushings ulcers (direct vagus nerve stimulation)
81
Common serum tumor markers
Alpha fetoprotein: hepatocellular carcinoma and germ cell tumors
CA 19-9: pancreatic
CA 125: ovarian
Carcinoembryonic antigen: GI (colorectal)
HCG: choriocarcinoma and germ cell tumors
PSA: prostate
82
Diffuse esophageal spasm (DES)
Periodic, simultaneous and non-peristaltic contractions of the esophagus due to impaired inhibitory innervation within the esophageal myenteric plexus. Present w dysphagia, and chest pain. "Corkscrew" esophagus on barium esophogram
83
Adenocarcinoma at the head of the pancreas
Palpable but non tender gallbladder (Courvoisier sign), weight loss and obstructive jaundice (assoc w pruritis, dark urine, and pale stools)--> cancer of the head of the pancreas compressing the bile duct
84
Chronic mesenteric ischemia
Atherosclerosis of the mesenteric arteries, resulting in diminished blood flow to the intestine after meals. Causes post prandial epigastric pain ("intestinal angina") w associated food aversion/weigh loss. Similar to angina pectoris
85
Beta glucouronidase
Bacterial or helminthic infection of the biliary tract results in the release of beta-glucouronidase by injured hepatocytes and bacteria. Hydrolyzes bilirubin glucouronides and increases the amount of unconjugated bilirubin -> development of brown pigment gallstones
-common in East Asian countries
