07a: GI Flashcards
1
Q
Between (X) weeks of embryological development, you would expect the physiologic midgut to be herniated outside the abdominal cavity.
A
X = 6-10
2
Q
Ventral wall defects: failure of rostral fold closure during development
A
Sternal defects (ectopia cordis)
3
Q
Ventral wall defects: failure of lateral fold closure during development
A
- Omphalocele
2. Gastroschisis
4
Q
Ventral wall defects: failure of caudal fold closure during development
A
Bladder exstrophy
5
Q
Abdominal protrusion in newborn that’s covered by skin
A
Umbilical hernia (incomplete closure of umbilical ring)
6
Q
Neonate with abdominal distension and bilious vomiting likely has obstruction before/after which part of GI tract?
A
Small bowel, after second part of duodenum
7
Q
Duodenal atresia is due to an issue with (X) process. Jejunal/ileal atresia is due to an issue with (Y) process.
A
X = recanalization Y = blood supply (ischemic necrosis and segmental resorption due to disruption of mesenteric vessels)
8
Q
Neonate presenting with non-bilious projectile vomiting and olive-shaped mass in epigastric region
A
Hypertrophic pyloric stenosis
9
Q
Hypertrophic pyloric stenosis is associated with (X) exposure.
A
X = macrolide
10
Q
Which acid/base disturbance is seen in Hypertrophic pyloric stenosis?
A
Metabolic alkalosis (hypokalemic, hypochloremic) due to vomiting acid and volume contraction
11
Q
Annular pancreas refers to which anomaly?
A
Ventral bud abnormally encircles and compresses/narrows 2nd part of duodenum
12
Q
Pancreas divisum refers to which anomaly?
A
Failure of ventral and dorsal buds to fuse (common, mostly asymptomatic; may cause pancreatitis)
13
Q
(X) part of GI tract receives foregut blood supply but actually arose from (Y).
A
X = spleen Y = mesoderm (stomach mesentery)
14
Q
Which part(s) of small/large bowel are retroperitoneal
A
- Duodenum (parts 2-4)
2. Ascending and descending colon
15
Q
(Liver/gallbladder/pancreas/spleen) is/are retroperitoneal
A
Pancreas (except tail)
16
Q
Portal triad is contained in (X) ligament. Umbilical vein remnant, aka (Y), is contained in (Z) ligament.
A
X = hepatoduodenal (bile duct, proper hepatic a, portal v) Y = Round ligament (ligamentum teres) Z = Falciform (connects liver to anterior abdominal wall)
17
Q
Which ligaments are part of the lesser omentum?
A
Gastrohepatic and hepatoduodenal
18
Q
List the layers of gut wall, from inside to outside, as well as their contents
A
“MSMS”
- Mucosa (epithelium, LP, muscularis mucosa)
- Submucosa (meiSSner plexus, Secretory glands)
- Muscularis externa (Myenteric/auerbach plexus for Motility)
- Serosa (if intraperitoneal) or adventitia (retroperitoneal)
19
Q
Basal electric rhythm (number of waves/min) is highest/most frequent in (stomach/duodenum/ileum)
A
Duodenum (12 waves/min); stomach is 3, ileum is 8-9
20
Q
Brunner glands in (X) part of GI tract are responsible for secreting:
A
X = duodenum
HCO3
21
Q
Largest number of goblet cells found in which part of small bowel?
A
Ileum
22
Q
Intestinal crypts (of Lieberkühn) have (X) cells that secrete TNF as well as:
A
X = Paneth
Defensins, lysozyme
23
Q
Peyer’s patches would most likely be found where in GI tract?
A
Ileum
24
Q
Abdominal aorta bifurcates into (X) branches at which level of spine?
A
X = common iliacs
L4 (“biFOURcation)
25
Which branches come off the abdominal aorta laterally before the celiac trunk?
Inferior phrenic (off of which branches the superior suprarenal)
26
Which branches come off the abdominal aorta laterally between SMA and IMA?
1. Renal (off of which branch inferior suprarenal)
| 2. Gonadal
27
SMA syndrome: (X) is compressing (Y).
```
X = SMA and abdominal aorta
Y = transverse (3rd) part of duodenum
```
28
Bilious vomiting in neonate and fibrous bands extending from cecum/right colon to retroperitoneum
Midgut malrotation (resulting in cecum placement in RUQ and fibrous bands compressing duodenum)
29
Derivatives of the ventral pancreatic bud:
Uncinate process, inferior part of head, and proximal part of main pancreatic duct
30
Lymph drainage of rectum
Prox to dentate line: inferior mesenteric and internal iliac
| Distal to line: superficial inguinal
31
R and L colic lymph nodes drain:
R: upper ascending colon
L: splenic flexure and upper descending colon
32
Where is the location of the duodenal bulb? Ulcer perforation posteriorly will likely affect which vessel?
```
From pylorus to neck of gallbladder;
Gastroduodenal a (life-threatening hemorrhage)
```
33
Portal-systemic anastamosis involved in esophageal varices
Left gastric vein to esophageal vein (a branch of azygos v)
34
Portal-systemic anastamosis involved in caput medusae
Paraumbilical v to small epigastric vv (of anterior abdominal wall)
35
Portal-systemic anastamosis involved in anorectal varices
Superior rectal v to middle/inferior rectal vv
36
Portal hypertension with esophageal/anorectal varices treated with:
Transjugular Intrahepatic Portosystemic Shunt (TIPS) between portal v and hepatic v (bypass liver)
37
Above pectinate line: list arterial supply and venous drainage
Arterial: superior rectal a (off IMA)
Venous: superior rectal v (to IMV to splenic to portal v)
38
Above pectinate line, (X) cancer. Below, (Y) cancer.
```
X = adenocarcinoma (endoderm)
Y = squamous cell carcinoma (ectoderm)
```
39
Below pectinate line: list arterial supply and venous drainage
Arterial: Inferior rectal a (off internal pudendal)
Venous: Inferior rectal v (to internal pudendal to internal iliac, to common iliac, to IVC)
40
Liver: blood flow (from/toward) central vein and bile flow (from/toward) central vein.
Toward (from hepatic a and portal v branches)
| From (toward bile ductule)
41
Liver: Zone (I/II/III) most affected by alcoholic hepatitis and (first/last) zone affected by ischemia.
III;
| First
42
Liver: Zone (I/II/III) most affected by yellow fever.
II (yeLLow fever)
43
Liver: Zone (I/II/III) most affected by viral hepatitis.
I
44
Liver: Zone (I/II/III) most susceptible to ingested toxins (ex: cocaine). And Zone (I/II/III) most susceptible to metabolic toxins.
I;
| III
45
Liver: Zone (I/II/III) contains CYP450 system
III
46
List the layers of the spermatic cord, from inside to outside, and include the structure that each layer is derived from.
"ICE tie"
1. Internal spermatic fascia (transversalis fascia)
2. Cremasteric muscle and fascia (internal oblique)
3. External spermatic fascia (external oblique)
47
Deep inguinal ring is a physiologic opening in (X). And external inguinal ring is opening in (Y).
```
X = transversalis fascia
Y = external abdominal oblique aponeurosis
```
48
Gastrin secreted by (X) cells in (Y)
```
X = G
Y = antrum (stomach) and duodenum
```
49
H. pylori (directly/indirectly) (increases/decreases) Gastrin production.
Indirectly increases (via decreasing D cells/somatostatin levels)
50
Somatostatin, produced by (X) cells, is (increased/decreased) by vagal stimulation and functions to (increase/decrease):
X = D (pancreatic islets, GI mucosa); decreased
Decrease nearly everything:
1. Gastric acid/pepsinogen secretion
2. Pancreatic/small intestine secretion (including glucagon and insulin)
3. Gallbladder contraction
51
Gallbladder contraction and pancreatic secretion is stimulated by (X) substance, produced in (Y) cells.
```
X = cholecystokinin (CCK)
Y = I cells (duodenum, jejunum)
```
52
Which regulatory substance is primarily responsible for both endocrine and exocrine pancreatic secretions?
CCK (bicarb from ductal cells, enzymes from acinar cells);
Secretin also helps with bicarb secretion
53
T/F: Secretin is released from S cells in presence of high pH.
False - low pH (decreases gastric acid secretion)
54
GIP is released from (X) cells and functions to:
X = K cells (duodenum, jejunum)
Increase insulin secretion (endocrine) and decrease gastric acid secretion (exocrine)
55
Motilin is secreted in (fasting/fed) state and functions to:
Fasting (from small intestine)
Produce migrating motor complexes (MMCs)
56
Intestinal water and electrolyte secretion is increased by vagal stimulation and release of:
VIP
57
VIPoma causes which symptoms?
"WDHA syndrome": Watery Diarrhea, Hypokalemia, Achlorydia
58
List the 3 main stimulators for gastric acid secretion:
"GAHstric acid"
1. Gastrin
2. ACh
3. His
59
Which phase of acid secretion is triggered just by thought/sight/smell of food?
Cephalic (first phase)
60
List the phases of gastric acid secretion
1. Cephalic
2. Gastric
3. Intestinal
61
Peptide YY is released by (X) portions of GI tract and functions to:
X = ileum and colon (during intestinal phase of acid secretion)
Binds receptors on ECL (enterochromaffin-like) cells, blocking gastrin action on the cells for His release
62
Gastric mucosa: large, oxyntic/pale pink cells in glands on histology are secreting (X)
X = gastric acid and intrinsic factor
Parietal cells
63
Gastric mucosa: small, basophilic cells in glands on histology are secreting (X)
X = pepsinogen
Chief cells
64
Crohn's disease: increase risk of (X) urinary stones via which mechanism?
X = oxalate
Decreased bile acid reabsorption (terminal ileum) means decreased fat reabsorption; fat binds to Ca, which then can't bind oxalate for excretion, so increased oxalate reabsorption
65
Which pancreatic enzymes are secreted in active form?
Lipase and amylase
66
Enterocytes absorb which carbohydrates? Via which apical and basal transporters?
1. Glucose (SGLT1; Na dependent)
2. Galactose (SGLT1; Na dependent)
3. Fructose (GLUT5; passive transport)
All transported to blood by GLUT2
67
Where are folate and vit B12 primarily absorbed in GI tract?
Folate: small bowel (jejunum)
B12: terminal ileum
68
Where is Fe primarily absorbed in GI tract?
Duodenum
69
Peyer patches location
Lamina propria and submucosa of ileum
70
Rate-limiting step in bile act synthesis carried out by which enzyme?
Cholesterol 7a-hydroxylase
71
Bruises turn greenish color due to action of:
Heme oxygenase (metabolizes heme into biliverdin)
72
Conjugated bilirubin formed by action of which enzyme?
UDP-glucoronosyl-transferase
73
Achalasia is due to:
Loss of myenteric (Auerbach) plexus and inhibitory neurons (NO, VIP) in esophagus; absent peristalsis and high LES pressure
74
Achalasia may be secondary to (X) infection.
X = Trypanosoma cruzi (Chagas disease)
75
T/F: Achalasia is associated with increased risk esophageal cancer.
True - both squamous cell and adenocarcinoma
76
Boerhaave syndrome:
TRANSMURAL (unlike Mallory-Weiss syndrome), distal esophageal rupture with pneumomediastinum due to violent retching
77
Which X-ray sign would you most commonly find with Boerhaave syndrome?
Pneumomediastinum (stripe of air adjacent to heart/aorta)
78
Esophagitis with white pseudomembrane:
Candida infection (immunocompromised pts)
79
Esophagitis with punched-out ulcers:
HSV-1 (immunocompromised pts)
80
Esophagitis with linear, shallow ulcers
CMV (immunocompromised pts)
81
What are some less common symptoms of GERD?
"Silent GERD" can present as chronic (nocturnal) cough, hoarseness
82
Which structural abnormality is a predisposing factor to Mallory-Weiss syndrome?
Hiatial hernia
83
Plummer-Vinson syndrome increases risk for which esophageal pathology?
Squamous cell carcinoma
84
Pathogenesis/mechanism of esophageal complications in Scleroderma:
Esophageal smooth muscle atrophy (fibrous replacement of muscularis) decreases LES pressure and causes dysmotility
85
Pt with history of DM II, obesity, and severe GERD presents with new onset odynophagia. Most likely diagnosis?
Ulcer formation (erosive esophagitis)
86
Corkscrew shape of esophagus on barium swallow:
Diffuse esophageal spasm (disorganized, non-peristaltic contractions due to impaired inhibitory neurotransmission within myenteric plexus)
87
List some causes of acute gastritis
(Usually stress-related mucosal damage)
1. NSAIDs
2. Burn (Curling ulcer)
3. Brain injury (Cushing ulcer)
88
Curling ulcer: mechanism of injury
Burns lead to hypovolemia and mucosal ischemia (erosion/ulcer and acute gastritis)
89
Cushing ulcer: mechanism of injury
Brain injury leading to high vagal stimulation, high ACh, and high gastric acid production (erosion/ulcer and acute gastritis)
90
Chronic gastritis: mucosal (hypertrophy/atrophy/hyperplasia) and (hyper/hypo)-chlorydia. Two main causes, star the most common.
Mucosal atrophy (chronic inflammation); hypochlorydia (and hypergastrinemia, leading to G cell metaplasia)
1. H. pylori*
2. Autoimmune
91
T/F: Both ulcer formation and gastric adenocarcinoma are more common in autoimmune/atrophic than H. pylori chronic gastritis.
False - ulcers more common with H. pylori; adenocarcinoma more common with autoimmune cause
92
(X) disease: precancerous (hyper/hypo)-plasia of gastric mucosa and stomach rugae that look like brain gyri.
X = Ménétrier
Hyperplasia (hypertrophied rugae)
Excess mucus production, parietal cell atrophy
93
(Diffuse/intestinal) gastric cancer associated with H. pylori infection as well as which other risk factors?
Intestinal;
| Nitrosamines (smoked food), tobacco smoking, achlorhydria, chronic gastritis
94
(Diffuse/intestinal) gastric cancer: leathery, thickened stomach wall. What would you see on histology?
Diffuse
| Signet ring cells (mucin-filled)
95
You would expect weight loss with (gastric/duodenal) ulcer. Why?
Gastric;
pain Greater with meals in Gastric ulcer
pain Decreases with meals in Duodenal ulcer
96
NSAIDs can cause (gastric/duodenal) ulcers. H. pylori can cause (gastric/duodenal) ulcers. ZES can cause (gastric/duodenal) ulcers.
Gastric;
Both;
Duodenal
97
T/F: Biopsy should be done on all gastric and duodenal ulcers.
False - duodenal ulcers rarely malignant, so no biopsy needed
98
Small intestinal bacterial overgrowth associated with increased serum levels of:
Vit K and folate (produced by enteric bacteria)
99
Celiac disease histology:
1. Villous atrophy
2. Crypt hyperplasia
3. Intraepithelial lymphocytosis
100
T/F: Celiac disease increases risk of malignancy.
True - ex: T cell lymphoma
101
Lactose intolerance: what's the mechanism of the diarrhea?
Osmotic
102
Lactose intolerance can be diagnosed via (X) test. What's the mechanism behind this?
X = hydrogen breath test
Bacterial ferment lactose and produce hydrogen (note: this also acidifies the stool)
103
Ito cells are found in (X) and have which functions?
AKA hepatic stellate cells
X = liver (space of Disse)
Normally store vit A (quiescent) and can be activated to produce extracellular matrix (ex: collagen scar tissue leading to cirrhosis)
104
T/F: Alcoholic cirrhosis are deficient in vitamin A.
True - Ito cell store of Vit A decreases when they're activated to produce ECM
105
Schilling test used to assess:
Vit B12 deficiency cause
106
Tropical sprue is similar to (X) disease, but responsive to (Y). Which vitamin/mineral deficiencies are seen?
```
X = celiac sprue
Y = antibiotics (unknown cause)
```
Vit B12 and folate (megaloblastic anemia)
107
Whipple disease symptoms and histological findings:
"PASs the FOAMY WHIPPed cream in the CAN"
PAS positive, foamy macrophages in lamina propria; diarrhea/steatorrhea
1. Cardiac Sx
2. Arthralgias
3. Neuro Sx
108
T/F: D-xylose test normal in pancreatic insufficiency.
True - no need for pancreatic enzymes for monosaccharide absorption (test used to distinguish pancreatic insufficiency versus mucosa defect/bacterial overgrowth)
109
"Lead pipe" colon on barium enema:
Ulcerative colitis (loss of haustra)
110
"String sign" bowel on barium swallow Xray
Crohn's (bowel wall thickening)
111
Crohn's disease is (TH1/TH2) mediated and UC is (TH1/TH2) mediated
TH1 (non-caseating granulomas; IL2, TNF, IFN-g)
| TH2 (IL4-6, IL10)
112
Recurrent UTIs and pneumaturia seen in (Crohn's/UC).
Crohns (enterovesical fistula formation)
113
Mechanism of toxic megacolon is increased (X) causing smooth muscle paralysis
X = NO
114
Primary sclerosing cholangitis associated with (Crohn's/UC)
UC
115
NOD2 gene mutation increases susceptibility to (X) disease. What's the mechanism behind this?
X = Crohn's
Decreased NF-kB activation so decreased cytokine production and innate immunity; this impairs intestinal mucosa immune response, so luminal bac penetrate tissue; exaggerated adaptive immune system response causes chronic inflammation
116
Most likely inciting event in appendicitis in kids
Lymphoid hyperplasia (ex: post-viral illness) causing obstruction
117
Diverticulitis symptoms and Rx
Similar to appendicitis (fever, leukocytosis, localized abdominal pain), but in LLQ and more common in elderly
Rx: antibiotics
118
Zenker diverticulum: herniation at which location?
Killian triangle (inferior pharyngeal constrictor, between thyropharyngeal and cricopharyngeal parts)
119
Characteristics of Meckel diverticulum
The rule of TRUE 2's:
1. True diverticulum
2. 2x more likely in males
3. 2% of population
4. 2 inches long
5. 2 feet from ileocecal valve
6. May have 2 types of epithelia (gastric/pancreatic)
120
Pertechnetate study localizing to RLQ
Meckel diverticulum (pertechnetate uptake by ectopic gastric mucosa/parietal cells)
121
Most common Sx in meckel diverticulum
Painless GI bleeding
122
Key clinical finding that distinguishes meconium ileus from hirschsprung disease
Hirschsprung: empty rectum on digital exam and positive "squirt" sign (explosive expulsion of feces)
MI: Negative squirt sign, rectum not empty
123
T/F: Hirschsprung disease treated by resecting affected segment.
True
124
Volvulus in infants/children more common in (X) part of GI tract. In elderly, more common in (Y) part
```
X = midgut
Y = sigmoid
```
125
Majority of intussusception causes occur in (X) patient population and may be associated with which causes?
X = kids (*Most common cause of GI obstruction in kids 3 months - 6 years old)
Meckel div, recent viral infection (adenovirus) and peyer patch hypertrophy
126
Intussusception commonly occurs at (X) part of GI tract and presents with which Sx?
X = ileocecal junction
| Intermittent abdominal pain (with pain-free periods) and currant jelly stools
127
60 yo patient with hematochezia and thumbprint sign on abdominal Xray
Colonic ischemia (thumbprint sign due to edema/hemorrhage of mucosa)
128
65 yo pt with Hx of CAD, angina, and previous MI presents with post-prandial epigastric pain and weight loss. What diagnosis is near the top of your differential?
Chronic mesenteric ischemia
| "intestinal angina" due to atherosclerosis of celiac a, SMA, IMA
129
Angiodysplasia:
Tortuous dilation fo vessels causing hematochezia (AV malformation)
130
Most common cause of bowel obstruction:
Adhesions (fibrous bands of scar after surgery)
131
Thick, dehydrated mass obstructing intestine (esp distal ileum) and preventing stool passage in newborn
Meconium ileus (cystic fibrosis)
132
Premature infant develops bilious vomiting and imaging shows portal venous gas. What's the likely diagnosis and mechanism?
Necrotizing enterocolitis
Immature immune system allows bacteria to enter/damage intestinal tissues, leading to necrosis of mucosa and perforation
133
Villous adenoma/polyp can cause which electrolyte abnormalities?
Hypokalemia (secrete large V of watery mucus causing secretory diarrhea and hypovolemia)
134
Serrated colonic polyps: (malignant/benign) via (X) pathway with microsatellite (stability/instability) and mutations in (Y).
Pre-malignant
X = CpG hypermethylation
Instability
Y = BRAF
135
Adenomatous colonic polyps: (X) pathway with mutations in (Y).
```
X = chromosomal instability
Y = APC and KRAS
```
136
T/F: All inherited polyposis syndromes are autosomal dominant
True
137
FAP: mutation in (X) on chromosome (Y). Which part of GI tract always involved?
```
X = APC (tumor suppressor)
Y = 5q
```
Rectum (thousands of polyps arise after puberty)
138
Patient with FAP has (X)% change of colorectal cancer.
X = 100
Hence prophylactic colectomy in these pts
139
What's Turcot syndrome?
A polyposis syndrome; FAP/Lynch plus malignant CNS tumors (medulloblastoma, glioma)
"TURcot = TURban (brain involved)"
140
(X) syndrome: hyperpigmented macules on lips, hands, genitalia along with which other key finding?
X = Peutz-Jeghers
Numerous hamartomas (benign polyps) throughout GI tract (increased risk of breast and visceral cancers)
141
T/F: Lynch syndrome involves MSH1/MSH2 gene mutation, numerous colonic polyps, microsatellite instability, and 80% progression to CRC.
Mostly true, except NOT a polyposis syndrome so no numerous colonic polyps (hence previous name "HNPCC")
142
Patient with Lynch syndrome is at risk for which cancers?
CRC (80%), endometrial, ovarian, skin
143
List the locations of colon where CRC tends to occur, in order of most to least common.
1. Rectosigmoid
2. Ascending
3. Descending
144
Chromosomal instability pathway for CRC: which mutations occur, in order?
AK-53
```
APC gene loss (colon at risk)
KRAS mutation (adenoma)
p53 loss (carcinoma; "the last hit")
```
145
NSAIDs (increase/decrease) risk for CRC because:
Decrease
| COX2 over-expression has been linked to CRC
146
Esophageal varices, splenomegaly in 48 yo M with normal liver biopsy. Most likely diagnosis?
Portal vein thrombosis
147
T/F: One of first signs of cirrhosis is low albumin levels.
False - coagulation disorder (esp low F VII) due to shorter half-life than albumin
148
Patient with history of cirrhosis and ascites presents with fever/chills, abdominal pain, and asterixis. What would be the next step in aiding your diagnosis?
Paracentesis of ascitic fluid to check for spontaneous bacterial peritonitis (absolute PMN count over 250 cells/mm3)
149
Patient with Hx of liver disease comes in for routine exam. His AST is higher than his ALT. What are two potential reasons for this?
1. Alcoholic liver disease
| 2. Non-alcoholic but progression of liver disease to advanced fibrosis/cirrhosis
150
Which primary markers for assessing liver function hold the greatest prognostic significance in cirrhosis patients?
1. Bilirubin
2. Albumin
3. PT
Note: AST/ALT measure liver intactness/integrity NOT function
151
Reye syndrome: describe the liver changes/damage and the mechanism by which it occurs.
```
Fatty liver (microvesicular fatty change)
Aspirin metabolites decrease beta-oxidation (via reversible inhibition of mitochondrial enzymes)
```
152
28 yo missionary, recently returned from South America, presents with fever, anorexia, nausea, and rash. High AST, ALT (ALT > AST), prolonged PT time. Viral serologies are negative. Likely diagnosis?
Drug-induced (halothane anesthetic) liver injury (especially if had surgery abroad)
153
Drug-induced liver injury from halothane: what would you expect to see on autopsy/histology?
Liver atrophy on autopsy;
Histo: widespread centrilobular necrosis and inflammation of portal tracts/parenchyma (indistinguishable from viral hepatitis)
154
Drug-induced liver injury from halothane: what's the mechanism?
Immune-mediated (attack hepatocytes)
155
Pyogenic liver abscess that got to liver through hepatic artery: most likely organism?
S. aureus (systemic hematogenous route)
