GI Flashcards
1
Q
Gastroschisis
A
Extrusion of abdominal contents through abdominal folds (typically right of umbilicus); not covered by peritoneum or amnion
2
Q
Omphalocele
A
Persistent herniation of abdominal contents into umbilical cord, covered by peritoneum
3
Q
Esophageal atresia with distal tracheoesophageal fistula
A
Polyhydramnios in utero; neonates drool, choke, and vomit with 1st feeding
4
Q
Duodenal atresia
A
Intestinal atresia
Bilious vomiting and abdominal distension within 1–2 days of life
“Double bubble”
Associated with Down syndrome
5
Q
Jejunal and ileal atresia
A
Disruption of mesenteric vessels -> ischemic necrosis -> segmental resorption (bowel discontinuity or “apple peel”)
6
Q
Hypertrophic pyloric stenosis
A
Palpable olive-shaped mass in epigastric region, visible peristaltic waves, and nonbilious projectile vomiting at ∼2–6 weeks
7
Q
Falciform ligament
A
Connects Liver to anterior abdominal wall
Contains Ligamentum teres hepatis
Derivative of ventral mesentery
8
Q
Hepatoduodenal ligament
A
Connects Liver to duodenum
Contains Portal triad: proper hepatic artery, portal vein, common bile duct
9
Q
Gastrohepatic ligament
A
Connects Liver to lesser curvature of stomach
Contains gastric arteries
Separates greater and lesser sacs on the right
10
Q
How do you treat portosystemic anastomoses cause by portal HTN
A
Transjugular intrahepatic portosystemic shunt (TIPS) between the portal vein and hepatic vein
11
Q
Venous drainage above the pectinate line
A
Superior rectal vein -> inferior mesenteric vein -> splenic vein -> portal vein
12
Q
What is the pectinate line?
A
Formed where endoderm (hindgut) meets ectoderm (divides the upper two thirds and lower third of the anal canal)
13
Q
Pathology that occurs above the pectinate line?
A
internal hemorrhoids, adenocarcinoma
14
Q
Blood supply above the pectinate line?
A
Superior rectal artery (branch of IMA)
15
Q
Venous drainage below the pectinate line
A
Inferior rectal vein -> internal pudendal vein -> internal iliac vein -> common iliac vein -> IVC
16
Q
Pathology that occurs below the pectinate line?
A
External hemorrhoids (painful d/t somatic innervation), anal fissures, squamous cell carcinoma
17
Q
Blood supply below the pectinate line?
A
Inferior rectal artery (branch of internal pudendal artery)
18
Q
Lymph drainage above the pectinate line?
A
To internal iliac lymph nodes
19
Q
Lymph drainage below the pectinate line?
A
To super cial inguinal nodes
20
Q
Kupffer cells
A
Specialized macrophages in the liver, form the lining of sinusoids
21
Q
Hepatic stellate (Ito) cells
A
In space of Disse store vitamin A (when quiescent) and produce extracellular matrix (when activated)
22
Q
What comprises the portal triad?
A
Bile ductule, Portal vein, Hepatic artery
23
Q
Pathology that affects Zone I first
A
Viral hepatitis Ingested toxins (cocaine)
24
Q
Pathology that affects Zone II first
A
Yellow fever
25
Pathology that affects Zone III first
Ischemia
Metabolic toxins
Alcoholic hepatitis
26
Courvoisier sign
Painless jaundice and enlarged gallbladder d/t adenocarcinoma of the head of the pancreas
27
What is contained in the femoral triangle?
Contains femoral nerve, artery, vein
28
What is contained in the femoral sheath?
Femoral vein, artery, and canal (deep inguinal lymph nodes)
29
Where does an indirect hernia protrude?
Through the deep (internal) inguinal ring, lateral to the epigastric vessels and into the scrotum
30
Where does a direct hernia protrude?
Protrudes through the inguinal (Hesselbach) triangle directly through parietal peritoneum medial to inferior epigastric vessels but lateral to rectus abdominis
Through the external (super cial) inguinal ring only
31
What is the most common diaphragmatic hernia?
Hiatal hernia: stomach herniates through the esophageal hiatus
32
Where does a femoral hernia protrude?
Below inguinal ligament through femoral canal below and lateral to pubic tubercle
33
Source, action and regulation of gastrin?
G cells in antrum and duodenum
Increases: acid secretion, gastric mucosa, gastric motility
Increased by stomach dissension, ↑ pH, AA, vagal stimulation
34
States that increase gastrin release?
Chronic PPI use
Chronic atrophic gastritis
Zollinger-Ellison
35
Source, action and regulation of Somatostatin?
D cells (pancreatic islets and GI mucosa)
Decreases: gastric acid, pepsinogen, pancreatic fluids, gallbladder contraction, insulin release
Increased by acid and decreased by vagal stimulation
36
What is octreotide an analogue of?
Somatostatin
37
Source, action and regulation of cholecystokinin?
I cells (duodenum, jejunum)
Increases: pancreatic secretion, gallbladder contraction and sphincter relaxation; decrease gastric emptying
Increased with FA and AA
38
Source, action and regulation of Secretin?
S cells (duodenum)
Increases: pancreatic HCO3 and bile; decreases gastric acid
Increased by low pH, FA
39
Source, action and regulation of glucose dependent insulinotropic peptide (GIP)?
```
K cells (duodenum, jejunum)
Exocrine function: decreases gastric H
Endocrine function: increases insulin release
Increased by FA, AA, oral glucose
```
40
Source, action and regulation of Motilin?
Small intestin
Produces migrating motor complexes
Increased when fasting
41
Source, action and regulation of vasoactive intetinal polypeptide?
PSNS ganglia in sphincter, gallbladder and small intestine
Increases: intestinal water secretion and smooth muscle relaxation
Increased by dissension and vagal stimulation
Decreased by adrenergic
42
What is a VIPoma?
non-α, non-β islet cell pancreatic tumor that secretes VIP
| Watery Diarrhea, Hypokalemia, and Achlorhydria
43
Source, action and regulation of Ghrelin?
Stomach
Increases appetite
Increased when fasting
44
Source, action and regulation of IF?
Parietal cells
| Bind B12 for uptake in ileum
45
Source, action and regulation of gastric acid?
Parietal cells
Decrease pH
Increased by histamine, ACh, gastrin
Decreased by somatostatin, GIP, prostaglandins and secretin
46
Source, action and regulation of Pepsin?
Chief cells
Aid protein digestin
Increased by X
47
α-amylase
Secreted by pancreas
| Digests starch
48
Lipase
Secreted by pancreas
| Digests fat
49
Protease
Secreted by pancreas
| Digests protein
50
Trypsinogen
Secreted by pancreas
| Converted to trypsin-> activates other enzymes
51
What is bilirubin conjugated with?
Glucuronate
52
Location of a salivary gland tumor
Parotid gland
53
Pleomorphic adenoma of salivary gland
Most common salivary gland tumor
| Composed of chondromyxoid stroma and epithelium and recurs if incompletely excised or ruptured intraoperatively
54
Mucoepidermoid carcinoma of salivary gland
most common malignant tumor, has mucinous and squamous components
55
Warthin tumor (papillary cystadenoma lymphomatosum)
benign cystic tumor with germinal centers
| Typically found in smokers
56
Achalasia
Failure of LES to relax d/t loss of myenteric (Auerbach) plexus
Will see bird's beak
57
Progressive dysphagia to solids and liquids
achalasia
58
Boerhaave syndrome
Transmural, usually distal esophageal rupture with pneumomediastinum d/t vomiting
59
Eosinophilic esophagitis
Infiltration of eosinophils in the esophagus often in atopic patients
Esophageal rings and linear furrows often seen on endoscopy
60
Mallory-Weiss syndrome
Partial-thickness mucosal lacerations at GE junction due to severe vomiting
61
Plummer-Vinson syndrome
Dysphagia, Iron de ciency anemia, and Esophageal webs
62
Barrett esophagus
Replacement of nonkeratinized stratified squamous epithelium with intestinal epithelium (nonciliated columnar with goblet cells) in distal esophagus.
63
Squamous cell carcinoma of esophagus
Upper 2/3
Incr risk with EtOH, hot liquids, smoking
Most common worldwide
64
Esophageal adenocarcinoma
Lower 1/3
Incr risk w/ GERD, smoking
More common in America
65
Causes of acute gastritis
NSAIDS (↓ PGE2 -> ↓ mucosa)
Burns (Curling ulcer): mucosal ischemia
Brain injury (Cushing ulcer): ↑ CNX -> ↑ ACh -> ↑ H production
66
Area of autoimmune gastritis
Body/Fundus
67
Ménétrier disease
Hyperplasia of gastric mucosa -> hypertrophied rugae
| Excess mucous, loss of protein, parental cell atrophy
68
Sister Mary Joseph nodule
subcutaneous periumbilical metastasis of gastric ca
69
Krukenberg tumor
Bilateral metastases of gastric ca to ovaries
| Abundant mucin-secreting, signet ring cells
70
Intestinal gastric ca
Associated with H pylori, dietary nitrosamines (smoked foods), tobacco smoking, achlorhydria, chronic gastritis
Commonly on lesser curvature; looks like ulcer with raised margins
71
Diffuse gastric ca
Signet ring cells
| Stomach wall grossly thickened and leathery (linitis plastica)
72
Abdominal pain that increases with meals
Gastric ulcer
73
Abdominal pain with decreases with meals
Duodenal ulcer
74
Complications with ruptured gastric ulcer on lesser curve
Bleeding from left gastric artery
75
Complications with ruptured ulcer on posterior wall of duodenum
Bleeding from gastroduodenal artery
76
Area affected in celiac
Distal duodenum and/or proximal jejunum
77
d-xylose test
Passively absorbed in proximal small intestine;
Decreased blood and urine levels with mucosa defects or bacterial overgrowth
normal in pancreatic insufciency
78
Pancreatic insufficiency will have
↓ duodenal pH (bicarb) and fecal elastase
| Malabsorption of fat and fat-soluble vitamins and vitamin B12
79
Whipple disease
PAS + (foamy macrophages)
Cardiac symptoms, Arthralgias, and Neurologic symptoms
Most common in older men
80
Location of Crohn disease
Any portion of the GI tract, usually the terminal ileum and colon
81
Morphology of Crohn disease
Skip lesions
| Cobblestones, creeping fat, string sign
82
Treatment for Crohn disease
Corticosteroids, azathioprine, antibiotics (cipro or metro), infliximab, adalimumab
83
Location of UC
Colon; always has rectal involvement
| Continuous lesions
84
Morphology of UC
Mucosal and submucosal inflammation
| Loss of haustra: “lead pipe”
85
Treatment for UC
5-aminosalicylic preparations (eg, mesalamine), 6-MC, infliximab, colectomy
86
Diverticulosis
Many false diverticula of the colon, commonly sigmoid.
87
Diverticulitis
Inflammation of diverticula
| LLQ pain, fever, leukocytosis
88
Zenker diverticulum
Pharyngoesophageal false diverticulum between the thyropharyngeal and cricopharyngeal parts of the inferior pharyngeal constrictor
89
Meckel diverticulum
True diverticulum. Persistence of the vitelline duct.
90
Hirschsprung disease cause
Congenital megacolon characterized by lack of ganglion cells/enteric nervous plexuses
Due to failure of NCC migration; RET mutation
91
Presentation of Hirschsprung disease
Bilious emesis, abdominal distention, and failure to pass meconium within 48h
92
Malrotation
Anomaly of midgut rotation during fetal development -> formation of fibrous bands (Ladd bands)
93
Volvulus
Twisting of portion of bowel around its mesentery
Midgut volvulus more common in infants and children
Sigmoid volvulus (coffee bean sign on XR) more common in elderly.
94
Intussusception
Commonly at ileocecal junction
| “Currant jelly” stools
95
Acute mesenteric ischemia
Often embolic occlusion of SMA-> small bowel necrosis
| “Currant jelly” stools
96
Chronic mesenteric ischemia
“Intestinal angina”: atherosclerosis of celiac artery, SMA, or IMA
Postprandial epigastric pain
97
Colonic ischemia
Crampy abdominal pain followed by hematochezia
| Thumbprint sign on imaging due to mucosal edema/hemorrhage
98
Angiodysplasia
Tortuous dilation of vessels -> hematochezia
| Most often found in the right-sided colon
99
Necrotizing enterocolitis
Seen in premature, formula-fed infants with immature immune system
100
Systemic Mastocytosis
Mast cell proliferation d/t KIT mutation
| Release histamine: flushing, hypotension, itching and increased gastric aid secretion
101
Colonic polyps
Flat, sessile, or pedunculated (on a stalk) on the basis of protrusion into colonic lumen
102
Hamartomatous polyps
Generally non-neoplastic
Solitary lesions do not transform.
Growths of normal colonic tissue with distorted architecture.
Associated with Peutz-Jeghers syndrome and juvenile polyposis.
103
Mucosal polyps
Generally non-neoplastic
Small, usually < 5 mm.
Look similar to normal mucosa.
Clinically insignicant.
104
Submucosal polyps
Generally non-neoplastic
| May include lesions such as lipomas, leiomyomas, fibromas, and others.
105
Hyperplastic polyps
Generally non-neoplastic
Generally smaller and predominantly located in the rectosigmoid region.
May occasionally evolve into serrated polyps and more advanced lesions.
106
Adenomatous polyps
Malignant potential
Neoplastic, via mutations in APC and KRAS
Tubular has less malignant potential than villous
107
Serrated polyps
Malignant potential
Premalignant, via CpG hypermethylationy with microsatellite instability and mutations in BRAF
"Saw-tooth” pattern of crypts
108
Familial adenomatous polyposis
Autosomal dominant mutation of APC tumor suppressor
Pancolonic; always involves rectum.
Prophylactic colectomy or else 100% progress to CRC.
109
Gardner syndrome
FAP + osseous and soft tissue tumors, congenital hypertrophy of retinal pigment epithelium, impacted/supernumerary teeth
110
Turcot syndrome
FAP/Lynch syndrome + malignant CNS tumor (eg, medulloblastoma, glioma)
111
Peutz-Jeghers syndrome
Autosomal dominant syndrome featuring numerous hamartomas throughout GI tract, along with hyperpigmented mouth, lips, hands, genitalia
↑ risk of breast and GI Ca
112
Juvenile polyposis syndrome
Autosomal dominant syndrome in children (typically < 5 years old) featuring numerous hamartomatous polyps in the colon, stomach, small bowel.
↑ risk of CRC
113
Lynch syndrome
Autosomal dominant mutation of DNA mismatch repair genes with subsequent microsatellite instability.
∼80% progress to CRC. Proximal colon always involved.
Associated with endometrial, ovarian, and skin cancers
114
Location of colorectal Ca
Rectosigmoid > ascending > descending
115
Presentation of colorectal Ca
Ascending—exophytic mass, iron deficiency anemia, weight loss
Descending—infiltrating mass, partial obstruction, colicky pain, hematochezia
(Right side bleeds; left side obstructs)
116
Dx of colorectal Ca
Iron de ciency anemia in males (especially > 50 years old) and postmenopausal females
Colonoscopy
“Apple core” lesion seen on barium enema x-ray
CEA tumor marker: good for monitoring recurrence
117
Pathogenesis of colorectal Ca
Mutation in APC cause FAP and sporadic CRC via A-C sequence (APC gene, KRAS mutation, loss of p53)
118
Cirrhosis
Diffuse bridging fibrosis (via stellate cells) and regenerative nodules
119
Elevated alkaline phosphatase
↑ in cholestasis (eg, biliary obstruction), infiltrative disorders, bone disease
120
Elevated γ-glutamyl transpeptidase
Various liver and biliary diseases (just as ALP can), but not in bone disease; associated with alcohol use
121
Albumin as a liver marker
↓ in advanced liver disease
122
Reye syndrome
Often fatal childhood hepatic encephalopathy
123
Alcoholic hepatitis
Swollen and necrotic hepatocytes with neutrophilic infiltration
Mallory bodies
124
Cause of Hepatic encephalopathy
Cirrhosis -> portosystemic shunts -> ↓ NH3 metabolism -> neuropsychiatric dysfunction
125
Treatment of hepatic enceophalopathy
Lactulose ( NH4+ generation) and rifaximin or neomycin (NH3 producing gut bacteria)
126
Cavernous hemangioma
Common, benign liver tumor
127
Hepatic adenoma
Rare, benign liver tumor, often related to oral contraceptive or anabolic steroid use
128
Budd-Chiari syndrome
Thrombosis or compression of hepatic veins with centrilobular congestion and necrosis -> congestive liver disease
129
α1-antitrypsin deficiency
Misfolded gene product protein aggregates in hepatocellular -> ER cirrhosis with PAS ⊕ globules
130
Gilbert syndrome
Mildly ↓ UDP-glucuronosyltransferase conjugation and impaired bilirubin uptake.
Asymptomatic or mild jaundice usually with stress, illness, or fasting
131
Crigler-Najjar syndrome, type I
Absent UDP-glucuronosyltransferase. Presents early in life; patients die within a few years
132
Dubin-Johnson syndrome
Conjugated hyperbilirubinemia due to defective liver excretion. Grossly black liver. Benign
133
Rotor syndrome
Looks like Dubin Jonson but liver is not dark; Due to impaired hepatic uptake and excretion
134
Cause of Hemochromatosis
Recessive mutations in HFE gene: abnormal iron sensing and ↑ intestinal absorption
135
Primary sclerosing cholangitis
Concentric “onion skin” bile duct fibrosis : alternating strictures and dilation with “beading” of intra- and extrahepatic bile ducts
Assoc w/UC, pANCA
136
Primary biliary cholangitis
Autoimmune reaction -> lymphocytic infiltrate;
+granulomas destruction of intralobular bile ducts
+AMA, Incr IgM
137
Secondary biliary cholangitis
Extrahepatic biliary obstruction -> incr pressure in intrahepatic ducts injury/ fibrosis and bile stasis
138
Ascending cholangitis
Charcot triad of cholangitis: Jaundice, Fever, RUQ pain
139
Dx acute pancreatitis
2 of 3:
- acute epigastric pain radiating to back
- serum amylase or lipase up to 3× upper limit of normal
- Characteristic imaging findings
140
Pancreatic adenocarcinoma
CA 19-9 tumor marker
| Migratory thrombophlebitis—redness and tenderness on palpation of extremities (Trousseau syndrome)
141
Misoprostol
A PGE1 analog: ↑ production and secretion of gastric mucous barrier, ↓ acid production
142
Sulfasalazine
A combination of sulfapyridine (antibacterial) and 5-aminosalicylic acid (anti-inflammatory)
Activated by colonic bacteria.
For UC and Crohn
143
Loperamide
Agonist at μ-opioid receptors; slows gut motility
144
Orlistat
Inhibits gastric and pancreatic lipase; use for weight loss
145
Aprepitant
Substance P antagonist
| Blocks NK1 receptors in brain
