GI Flashcards
1
Q
ursodiol MOA
A
Nontoxic bile acid. Increases bile secretion + decreases cholesterol secretion and absorption.
2
Q
ursodiol clinical use
A
PBC + gallstone prevention or dissolution.
3
Q
Orlistat MOA
A
inhibits gastric and pancreatic lipase, thus leading to decreased breakdown and absorption of dietary fats.
4
Q
Orlistat AE’s
A
steatorrhea + decreased absorption of fat-soluble vitamins.
5
Q
metoclopramide MOA
A
D2 receptor antagonist. Increases resting tone, contractility, LES tone, motility. Does not influence colon transport time.
6
Q
metoclopramide clinical use
A
diabetic and postsurgery gastroparesis, antiemetic
7
Q
metoclopramide contraindications
A
digoxin + diabetic agents + SBO or Parkinson disease (due to D2 receptor blockade)
8
Q
metoclopramide AE’s
A
parkinsonian effects, tardive dyskinesia, restlessness, drowsiness, fatigue, depression, diarhea.
9
Q
ondansetron MOA
A
serotonin antagonist + decreases vagal stimulation
10
Q
ondansetron AE’s
A
headache + constipation + QT interval prolongation
11
Q
Loperamide MOA
A
agonist at mu-opioid receptors; slows gut motility. Poor CNS penetration (low addictive potential)
12
Q
loperamide AE’s
A
constipation + nausea
13
Q
Sulfasalazine – MOA, clinical use, SE’s
A
Sally Westcott in a sulfur geiser/sulfasalazine. Pyramid with sulfur geiser on top on right + tree with bark and hailing on it/MOA = combination of sulfapyridine (antibacterial) + 5-aminosalicylic acid (anti-inflammatory). Bacteria on counter throwing lasso around her/activated by colonic bacteria. Rachel in wheelchair next to counter/can cause drug-induced lupus. Riding a dead sperm/toxicity = malaise + nausea + sulfonamide toxicity + reversible oligospermia. /clinical use = UC + Crohn disease.
14
Q
lactulose
A
osmotic laxative
15
Q
osmotic laxatives AE’s
A
diarrhea, dehydration.
16
Q
octreotide MOA
A
long-acting somatostatin analog; inhibits secretion of various splanchnic vasodilatory hormones.
17
Q
Octreotide AE’s
A
nausea, cramps, steatorrhea + increased rick of cholethiasis due to CCK inhibition.
18
Q
misoprostol MOA
A
PGE1 analog. increased production and secretion of gastric mucous barrier, decreases acid production.
19
Q
misoprostol mechanism as abortifacent
A
Ripens cervix
20
Q
Other use of misoprostol.
A
Maintains PDA.
21
Q
misoprostol AE’s
A
diarrhea
22
Q
bismuth, sucralfate MOA
A
binds to ulcer base, providing physical protection and allowing HCO3- secretion to reestablish pH gradient in the mucous layer.
23
Q
another use for bismuth, sucralfate
A
travelers’ diarrhea.
24
Q
shared AE of all antacids
A
hypokalemia
25
aluminum hydroxide AE's
constipation + hypophosphatemia + proximal muscle weakness + osteodystrophy + seizures
26
calcium carbonate AE's
hypercalcemia (milk-alkali syndrome) + rebound acid production
27
magnesium hydroxide AE's
Harvey milk (sean penn) from movie milk in middle of room giving magnus who’s benchpressing a blowjob: he’s shitting on a towel + IV pole next to him + is being shocked + riding a mini motorcycle/SE’s = diarrhea + hyporeflexia + hypotension + cardiac arrest.
28
What is a proton pump?
H+/K+ ATPase in stomach parietal cells.
29
ZES treatment
PPI
30
PPI AE's
Nate is banging Heidi on the table + magnus strong man on the table + carson with his ski gear at other end of table/SE’s = increased risk of C. diff infection + decreased serum Mg2+ with long-term use + atrophic gastritis + carcinoid tumors + headaches + GI disturbances. Rest of seats filled with skeletons/associated with osteoporosis and osteoporotic hip fractures (decreases calcium absorption;calcium carbonate requires an acidic environment for proper absorption).
31
H2 blocker MOA
reversible block of histamine H2 receptors --> decreased H+ secretion by parietal cells.
32
H2 Blocker AE's
- Cimetidine is the primary concern. Others are relatively free of these effects.
- CYP450 inhibitor + antiandrogen effects + can cross BBB (confusion, dizziness, headaches) and placenta + decreases renal excretion of creatinine.
33
ranitidine AE
Decreases renal excretion of creatinine.
34
Foregut region
pharynx t oduodenum
35
midgut region
duodenum to proximal 2/3 of transverse colon.
36
hindgut region
distal 1/3 of transverse colon to anal canal above pectinate line.
37
Midgut development
6th week--physiologic midgut herniates through umbilical ring.
10th week--returns to abdominal cavity + rotates around SMA, total 270 counterclockwise.
38
Defect in rostral fold closure
Sternal defects
39
Defect in lateral fold closure
Omphalocele, gastroschisis
40
defect in caudal fold closure leads to...
bladder exstrophy
41
gastroschisis
extrusion of abdominal contents through abdominal folds (typically right of umbilicus); not covered by peritoneum.
42
Most common tracheoesophageal anomalies
esophageal atresia with distal tracheoesophageal fistula (85%)
43
why does cyanosis occur with esophageal atresia?
Secondary to laryngospasm (to avoid reflux-related aspiration).
44
H-type esophageal atresia
Pure TEF. see FA
45
jejunal and ileal atresia pathophys
disruption of mesenteric vessels --> ischemic necrosis --> segmental resoprtion.
46
characteristic sign of jejunal and ileal atresia.
Bowel discontinuity or "apple peel."
47
epidemiology of hypertrophic pyloric stenosis
Most common cause of gastric outlet obstruction (1:600).
48
hypertrophic pyloric stenosis RF
Exposure to macrolides.
49
hypertrophic pyloric stenosis acid/base disturbance
hypokalemic hypochloremic metabolic alkalosis (vomiting of gastric acid and subsequent volume contraction).
50
pancreas embryology
Derived from foregut. Ventral pancreatic buds contribute to uncinate process and main pancreatic duct. Dorsal pancreatic bud alone becomes body, tail, isthmus, and accessory pancreatic duct. Both ventral and dorsal buds contribut to pancreatic head.
51
annular pancreas
ventral pancreatic bud abnormally encircles 2nd part of duodenum; forming ring of pancreatic tissue that may cause dudoenal narrowing and *nonbilious vomiting.
52
Pancreas divisum and timeframe
Ventral and dorsal parts fail to fuse at 8 weeks. Common and mostly asymptomatic, but may cause chronic abdominal pain and/or pancreatitis.
53
pancreas anatomy
codebook
54
SADPUCKER notes
Aorta AND IVC
2nd-4th parts of duodenum
Pancreas (except tail)
Esophagus (thoracic portion)
55
falciform connects
Liver to anterior abdominal wall
56
falciform contains
ligamentum teres hepatis
57
ligamentum teres hepatis derived from...
fetal umbilical vein
58
falciform derivative of...
ventral mesentery
59
hepatoduodenal connects...
liver to duodenum
60
hepatoduodenal
portal triad
61
pringle maneuver
Compressing hepatoduodenal ligament between thumb and index finger in omental foramen to control bleeding.
62
hepatoduodenal borders the...
omental foramen
63
omental foramen connnects
The greater and lesser sacs.
64
gastrohepatic connects
liver to lesser curvature of stomach
65
gastrohepatic contains
- gastric arteries
| - separates greater and lesser sacs on the right.
66
what do you need to cut to access the lesser sac?
gastrohepatic ligament
67
gastrocolic connects... forms..
- greater curvature and transverse colon.
| - part of greater omentum.
68
gastrocolic contains
gastroepiploic arteries
69
What separates greater and lesser sacs on the left?
gastrosplenic
70
gastrosplenic connects...forms...
- greater curvature and spleen
| - part of greater omentum
71
gastrosplenic contains
short gastrics, left gastroepiploic
72
splenorenal connects....
Spleen to posterior abdominal wall.
73
Splenorenal contains
splenic artery and vein + tail of pancreas
74
Layers of gut wall
```
inside to outside -- MSMS
Mucosa
Submucosa
Muscularis externa
Serosa
```
75
Mucosa contains...
epithelium, lamina propria, muscularis mucosa.
76
submucosa includes...function..
- Submucosal nerve plexus (Meissner).
| - Secretes fluid.
77
Muscularis externa includes...
Myenteric nerve plexus (Auerbach)
78
serosa caveat
Called serosa when intraperitoneal, adventitia when retroperitoneal.
79
erosions vs. ulcers
Ulcers can extend into submucosa, inner or outer muscular layer. Erosions are confined to mucosa.
80
Stomach basal rhythm
3 waves/min
81
Duodenum basal rhythm
12 waves/min
82
Ileum basal rhythm
8-9 waves/min
83
Muscularis composition
Inner circular layer, myenteric nerve plexus (Auerbach), outer longitudinal layer
84
Brunner glands
HCO3- secreting cells of submucosa.
85
Duodenum contains
Brunner glands + cytps of Lieberkuhn + villi and microvilli
86
histology of jejunum
Plicae circularis and crypts of Lieberkuhn.
87
Peyer patches
Lymphoid aggregates in lamina propria, submucosa.
88
Where are peyer patches?
Ileum
89
Ileum histology
peyer patches + plicae circulares + crypts of lieberkuhn.
90
Where are the largest number of goblet cells in the small intestine?
Ileum
91
Colon histology
Crypts of Lieberkuhn but no villi; abundant goblet cells.
92
abdominal aorta branches rule
Arteries supplying GI structures branch anteriorly. Arteries supplying non-GI structures branch laterally and posteriorly.
93
Middle suprarenal anatomic location.
T12
94
celiac trunk anatomic location.
T12
95
Fist lumbar anatomic location
L1
96
Renal anatomic location
L1
97
SMA anatomic location
L1
98
Gonadal anatomic location
Just above L2
99
IMA anatomic location
L3
100
Bifurcation of abdominal anatomic location
L4 (biFOURcation)
101
Common iliacs anatomic location
L5
102
SMA artery syndrome
1) presentation
2) anatomy
3) scenario
1) Intermittent intestinal obstruction symptoms (primarily postprandial pain)
2) Transverse (3rd) portion of duodenum is compressed between SMA and aorta.
3) Conditions associated with diminished mesenteric fat (eg, low body weight/malnutrition).
103
Foregut
1) arterial supply
2) PS innervation
3) vertebral level
4) structures supplied
1) Celiac
2) Vagus
3) T12/L1
4) Pharynx (vagus nerve only) and lower esophagus (celiac artery only) to proximal duodenum; liver, gallbladder, pancreas, spleen (mesoderm)
104
Midgut
1) arterial supply
2) PS innervation
3) vertebral level
4) structures supplied
1) SMA
2) vagus
3) L1
4) distal duodenum to proximal 2/3 of transverse colon
105
Hindgut
1) arterial supply
2) PS innervation
3) vertebral level
4) structures supplied
1) IMA
2) Pelvic
3) L3
4) distal 1/3 transverse colon to upper portion of rectum.
106
TIPS procedure
Transjugular intrahepatic portosystemic shunt (TIPS). Creates a shunt between portal vein and hepatic vein, thus relieving portal HTN by shunting blood to the systemic circulation, bypassing the liver.
107
Varices seen with portal hypertension
(gut, butt, and caput (medusa) --> esophageal, rectal (anorectal varices), caput medusa
108
portosystemic rectal anastomosis
superior rectal with middle and inferior rectal.
109
caput medusae anastomosis
Paraumbilical with small epigastric veins of the anterior abdominal wall.
110
esophageal varices anastomosis
left gastric with azygos
111
pectinate (dentate) line
Formed where endoderm (hindgut) meets ectoderm.
112
Venous drainage above pecinate line
Superior rectal vein --> ifnerior mesenteric --> portal system
113
lymphatic drainage above pectinate line
internal iliac lymph nodes
114
venous drainage below pectinate line
inferior rectal vein --> internal pudendal vein --> internal iliac vein --> common iliac vein --> IVC
115
lymphatic drainage below pectinate line
Superficial inguinal nodes.
116
Anal fissure RF's
low fiber diet + constipation.
117
Kupffer cells
Specialized macrophages that form the lining of sinusoids
118
Hepatic stellate (Ito) cells 1) location 2) function
1) space of Disse
| 2) store vitamin A (when quiescent), produce ECM when activated.
119
intermediate zone, pericentral vein (centrilobular) zone, intermediate zone
Zone 1 = periportal zone
Zone 2 = intermediate zone
Zone 3 = pericentral vein (centrilobular) zone
120
Site of alcoholic hepatitis
Zone III
121
yellow fever affects...
zone II
122
ingested toxins (eg cocaine) affect....
Zone I
123
zone affected 1st by ischemia
Zone III (farthest from arterial supply)
124
zone affected 1st by viral hepatitis
Zone I
125
ampulla of vater and 2) clinical significance
1) little widened space behind sphincter of oddi in head of pancreas (FA 347)
2) gallstones that lodge here an block both the common bile and pancreatic ducts causing "double duct sign" --> both cholangitis and pancreatitis.
126
cystic duct
Duct that drains gallbladder
127
painless juandice
pancreatic adenocarcinoma (usually ductal) in head of pancreas that causes of obstruction of common bile duct.
128
femoral region organization
NAVeL --> nerve, artery, vein, lymphatics
129
femoral triangle
contains femoral nerve, artery, vein
130
femoral sheath
fascial tube 3-4 cm below inguinal ligament. Contains femoral vein, artery, and canal (deep inguinal lymph nodes) but NOT femoral nerve.
131
femoral triangle borders
- superiorly by inguinal ligament.
- medially by medial border of adductor longus.
- laterally by medial border of sartorius muscle.
132
superficial inguinal ring
External obie standing in the middle of a golden ring/formed by opening in the external oblique muscle aponeurosis.
133
Deep inguinal ring
• Code: hole down to china beneath trannies/opening in the transversalis fascia.
134
Layers of inguinal canal
Obie Spear on outside, closer to bank with stomach covered in big sperm/external spermatic fascia derived from external oblique. Obie hanging from inside pulling testicles up with a rope/cremasteric muscle and fascia derived from internal oblique. Line of trannies with sperm that have buried into their stomachs/internal spermatic fascia derived from transversalis fascia.
135
Site of protrusion of direct hernia
abdominal wall
136
Site of protrusion of indirect hernia
deep inguinal ring
137
conjoined tendon
formed by transversus abdominis muscle + internal oblique muscle
138
umbilical hernia defect location
defect at linea alba
139
incarceration
hernia that can't be reduced.
140
strangulation
hernia that becomes ischemic and necrotic
141
presentation of complicated hernias
tenderness, erythema, fever.
142
structure defective in congenital diaphragmatic hernia and usual location
- pleuroperitoneal membrane.
| - left side (no liver for protection)
143
Site of protrusion of direct inguinal hernia
Hesselbach triangle. Bulges directly through abdominal wall.
144
Other details of direct inguinal hernia
- goes through external (superficial) inguinal ring only.
- covered by external spermatic fascia.
- usually in older men.
145
Femoral hernia epidemiology
usually females.
146
femoral hernia protrusion
Below inguinal ligament through femoral canal below and lateral to pubic tubercle.
147
caveat about femoral hernias
More likely to incarcerate or strangulate.
148
Inguinal (hesselbach) triangle
Inferior epigastric vessels, lateral border of rectus abdominis, inguinal ligament
149
Gastrin source and location
G cells (****antrum of stomach, duodenum)
150
gastrin action
increases gastric H+ secretion, growth of gastric mucosa, gastric motility.
151
gastrin 1) increased by 2) decreased by
1) stomach distention/alkalinization, amino acids, peptides, vagal stimulation via gastrin-releasing peptide (GRP)
2) ph
152
what increases gastrin production?
chronic PPI use, chronic atrophic gastritis (H pylori), ZES
153
Somatostatin source
D cells (pancreatic islets, Gi mucosa)
154
somatostain actions
decreases gastric acid and pepsinogen secretion + pancreatic and small intestine fluid secretion + gallbladder contraction + insulin and glucagon release
155
somatostain regulation
increased by acid, decreased by vagal stimulation.
156
CCK source
I cells (duodenum, jejunum)
157
CCK action
Increases pancreatic secretion + gallbladder contraction. Decreases gastric emptying. Increases sphincter of oddi relxation.
158
CCK regulation
Increased by fatty acids, amino acids.
159
How does CCK cause pancreatic secretion
Acts on neural muscarinic pathways.
160
Secretin source
S cells (duodenum)
161
Secretin actions
Increases pancreatic HCO3- secretion + bile secretion. Decreases gastric acid secretion. Functions to neutralize gastric acid in duodenum, allowing pancreatic enzymes to function.
162
Secretin regulation
Increased by acid, fatty acids in lumen of duodenum.
163
glucose-dependent insulinotropic peptide
another name for GIP.
164
GIP source
K cells (duodenum, jejunum)
165
GIP functions
Exocrine: decreases gastric H+ secretion.
Endocrine: increases insulin release.
166
GIP regulation
Increased by fatty acids, amino acids, oral glucose.
167
Why does oral glucose lead to increased insulin compared to IV
GIP secretion.
168
drug that that acts as a motilin receptor agonist
erythromycin
169
VIP source
PS ganglia in sphincters, gallbladder, small intestine
170
VIP functions
Increases intestinal water and electrolyte secretion + increases relaxation of intestinal smooth muscle and sphincters.
171
VIP regulation
Increased by distention and vagal stimulation, decreased by adrenergic input.
172
Why is there increased LEs tone in achalasia?
Loss of NO secretion.
173
Ghrelin source
stomach
174
Ghrelin clinical relevance
Increased in Prader-Willi, decreased after gastric bypass surgery.
175
gastric acid positive regulators
histamine, ACh, gastrin
176
gastric acid negative regulation
somatostatin, GIP, prostaglandin, secretin.
177
pepsin source and function
chief cells, protein digestion
178
Pepsin regulation
increased by vagal stimulation, local acid
179
Bicarbonate source
```
mucosal cells (stomach, duodenum, salivary glands, pancreas)
brunner glands (duodenum)
```
180
where does bicarbonate sit?
Trapped in mucus that covers the gastric epithelium.
181
How does gastrin increase gastric acid secretion?
Indirectly through enterochromaffin-like cells (ECL cells) leading to histamine release rather than through its direct effect on parietal cells.
182
Pancreatic secretions tonicity + flow variance
1) isotonic
2) low flow --> high Cl-
high flow --> high HCO3-
183
alpha-amylase caveat
secreted in active form. Doesn't need to be activated.
184
name some proteases
trypsin, chymotrypsin, elastase, carboxypeptidase.
185
How is trypsinogen converted to trypsin?
Enterokinase/enteropeptidase, a brush-border enzyme on duodenal and jejunal mucosa.
186
Glucose and galactose absorption
Taken up by SGLTI (Na+ dependent).
187
Fructose absorption
Facilitated diffusion by GLUT-5.
188
GLUT 2 function
transports all monosaccharides (glucose, galactose, and fructose) to blood.
189
Functon of D-xylose absorption test
Distinguishes GI mucosal damage from other causes of malabsorption.
190
B12 absorption caveat
absorbed with bile salts.
191
peyer patch and location
unencapsulated lymphoid tissue found in lamina propria and submucosa of ileum.
192
Where do IgA-secreting plasma cells sit? What are they derived from
Lamina propria. Derived from B cells when stimulated in germinal centers.
193
Composition of bile salts
Bile acids conjugated to glycine or taurine, making them water soluble.
194
Composition of bile
Bile salts + phospholipids + cholesterol + bilirubin + water + ions.
195
Enzyme catalyzing rate-limiting step of bile acid synthesis.
Cholesterol 7alpha-hydroxylase.
196
Bile functions
1) Digestion and absorption of lipids and fat-soluble vitamins.
2) Cholesterol excretion (body's only means of eliminating cholesterol)
3) Antimicrobial activity (via membrane disruption).
197
Bilirubin cycle
Heme is metabolized by heme oxygenase to biliverdin --> biliverdin reduced to bilirubin --> unconjugated bilirubin is removed from blood by liver, conjugated with glucuronate, and excreted in bile --> gut bacteria metabolize conjugated bilirubin to urobilinogen --> 80% of urobilinogen is excreted in feces as sercobilin (brown color of stool). 20% of urobilinogen remains in gut. Of that 20%, 10% goes to kidney and is excreted in urine as urobilin (giving urine yellow color) and 90% goes back through enterohepatic circulation to the liver.
198
Direct bilirubin
conjugated with glucuronic acid; water soluble.
199
Indirect bilirubin
Unconjugated; water insoluble.
200
Where does initial part of bilirubin cycle occur?
RBCS --> heme --> unconjugated bilirubin occurs in macrophages.
201
enzymes that conjugates bilirubin
UDP-glucuronosyl-transfease.
202
Benign/malignant pattern of salivary gland tumors.
Most commonly benign and in parotid gland. Tumors in smaller glands more likely malignant.
203
Typical presentation of salivary gland tumor
Painless mass/swelling.
204
What does facial pain or paralysis in a salivary gland mass suggest?
Malignant involvement of CN VII.
205
Most common salivary gland tumor
Pleomorphic adenoma
206
Pleomorphic adenoma characteristics and composition
Benign mixed tumor. Composed of chondromyxoid stroma and epithelium and recurs if incompletely excised or ruptured intraoperatively.
207
Most common malignant salivary gland tumor
mucoepidermoid carcinoma.
208
Another name for Warthin tumor
Papillary cystadenoma lymphomatosum.
209
Warthin tumor
Benign cystic tumor with germinal centers.
210
Causes of secondary achalasia
1) chagas disease 2) extraesophageal malignancies (mass effect or paraneoplastic)
211
Barium swallow finding of achalasia
birds break
212
achalasia characteristics
Failure of relaxation of LES due to loss of myenteric (Auerbach) plexus. High LES resting pressure and uncoordinated or absent peristalsis, leading to progressive dysphagia to solids and liquids.
213
Obstructive dysphagia presentation vs. achalasia
Obstructive dysphagia only occurs with solids, achalasia occurs with both liquids and solids.
214
Endoscopy findings in eosinophilic esophagitis
Esophageal rings and linear furrows.
215
patient presenting with GERD but unresponsive to GERD therapy consider...
eosinophilic esophagitis
216
Pathophys of food impaction in eosinophilic esophagitis
Food allergens --> dysphagia --> food impaction.
217
What causes esophageal strictures?
1) Caustic ingestion
| 2) Acid reflux
218
esophageal varices
dilated submucosal veins in lower 1/3 of esophagus secondary to portal HTN.
219
atypical but common presentation of GERD
cough + hoarseness (laryngopharyngeal reflux).
220
GERD association
asthma
221
Plummer-Vinson triad
dysphagia + iron deficiency anemia + esophageal webs
222
plummer vinson association
Glossitis
223
sclerodermal esophageal dystomility pathophys
esophageal smooth muscle atrophy --> decreased LES pressure and dysmotility --> acid reflux and dysphagia --> stricture, Barrett esophagus, and aspiration.
224
Barrett's cancer association
ADENOCARCINOMA
225
more common esophageal cancer worldwide
squamous cell carcinoma
226
RF's for esophageal adenocarcinoma
Chronic GERD, barrett's, obesity, smoking, achalasia
227
part of esophagus affected in squamous vs. adeno
Upper 2/3 = SCC
| Lower 1/3 = adeno
228
prostaglandin affected by NSAIDs
PGE2
229
Curling ulcers
Complications from severe burns. (burned by the curling iron)
230
Curling ulcer pathophys
hypovolemia --> mucosal ischemia.
231
Cushing ulcer
Ulcer resulting from brain injury (cushin the brain)
232
Cushing ulcer pathophys
Brain injury --> increased vagal stimulation --> increased ACh --> increased H+ production.
233
Chronic gastritis pathophys
Mucosal inflammation, leads to atrophy (hypochlorhydria --> hypergastrinemia) and intestinal metaplasia.
234
H pylori cancer association
MALT lymphoma
235
H pylori location
affects antrum first, then spreads to body of stomach.
236
autoimmune gastritis location of damage
body/fundus of stomach
237
menetrier benign/malignant?
precancerous
238
gastric cancer epidemiology
Gastric adenocarcinoma --> lymphoma --> GI stromal tumor --> carcinoid (rare).
239
Gastric cancer personality + presentation
Early aggressive local spread with node/liver metastases. Often presents late with weight loss + early satiety, acanthosis nigricans, leser-trelat.
240
Intestinal gastric cancer associations
H pylori, dietary nitrosamines (smoked foods), tobacco smoking, achlorhydria, chronic gastritis.
241
Intestinal gastric cancer location + what it looks like
Lesser curvature; looks like ulcer with raised margins.
242
Diffuse gastric cancer associations
NOT associated with H pylori. Signet ring cells; stomach wall grossly thickened and leathery (linitis plastica)
243
Krukenberg tumor histology
Abundnat mucin-secreting, signet ring cells.
244
Gastric ulcer pain vs. duodenal ulcer pain
Gastric, Greater with meals. Duodenal decreases with meals.
245
H pylori association with gastric or duodenal ulcers
Causes pretty much all duodenal ulcers and 70% of gastric ulcers.
246
Gastric ulcer management
Biopsy margins to rule out malignancy
247
Gastric ulcer benign/malignant?
Increased risk of carcinoma
248
Gastric ulcer mechanism
decreased mucosal protection against gastric acid.
249
Duodenal ulcer mechanism
decreased mucosal protection OR increased gastric acdi secretion
250
Other causes of duodenal ulcrs
ZES
251
duodenal ulcer -- benign/malignant?
Usually benign.
252
Duodenal ulcer association
hypertrophy of brunner glands
253
duodenal area prone to hemorrhaging
posterior more common than anterior.
254
Most common complication of ulcers
hemorrhaging
255
Artery associated with ruptured gastric ulcer on lesser curvature of stomach
left gastric
256
Artery associated with hemorrhaging ulcer on posterior wall of duodenum
gastroduodenal
257
Potential ulcer complications
1) hemorrhaging
2) obstruction (pyloric channel, duodenal)
3) perforation.
258
Area of duodenum prone to perforation.
anterior>posterior.
259
Free air under diaphragm with referred pain to shoulder via phrenic nerve....
perforated duodenum from duodenal ulcers.
260
cancer and celiac's?
moderately increased risk of T-cell lymphoma
261
histo findings in celiac's
villous atrophy + crypt hyperplasia + **intraepithelial lymphocytosis.
262
area primarily affected by celiac's
mucosal absorption decreased in distal duodenum and/or proximal jejunum.
263
Test for celiacs
1) serology for antibodies
| 2) d-xylose for malabsorption
264
d-xylose results
1) if blood and urine levels are decreased --> mucosal defect or bacterial overgrowth
2) if pancreatic insufficiency, then will be normal.
265
Material that accumulates in clear cell carcinoma
high in glycogen and lipids
266
lactose intolerance diagnosis + analyzing results
lactose hydrogen breath test. Positive for lactose malabsorption if postlactose breath hydrogen value rises > 20 ppm compared with baseline.
267
Thing to remember about pancreatic insufficiency
not only malabsorption of fat-soluble vitamins but also B12
268
Pancreatic insufficiency diagnosis
Decreased duodenal pH (bicarbonate) and fecal elastase.
269
region of intestine affected in tropical sprue
Duodenum + jejunum but can involve ileum.
270
anemia relationship to tropical sprue
due to folate deficiency, and, later, B12 deficiency.
271
ulcers in chrohn's
linear ulcers
272
microscopic morphology in crohn's
noncaseating granulomas + lymphoid aggregates.
273
Other complications of Crohn's
1) enterovesical fistula, which can cause recurrent UTI and pneumaturia.
2) phlegmon/abscess
3) strictures (causing obstruction)
4) perianal disease.
5) kidney stones
6) gallstones
274
antibiotics for Crohn's patients
Ciprofloxacin + metronidazole
275
UC gross morphology
1) Mucosal and submucosal inflammation only.
2) Friable mucosal pseudopolyps with freely hanging mesentery.
3) Loss of haustra --> "lead pipe" appearance on imaging
276
Complications of UC
1) Fulminant colitis
2) Toxic megacolon
3) Perforation
277
Primary sclerosing cholangitis lab finding
p-ANCA
278
UC treatment
5-aminosalicylic preparations (eg, mesalamine), 6-mercaptopurine, infliximab, colectomy.
279
IBS presentatoin
Recurrent abdominal pain associated with 2 of following
1) pain improves with defecation
2) change in stool frequency
3) change in appearance of stool.
- - can be diarrhea-predominant or constipation-predominant or mixed.
280
appendicitis pathophys
In adults --> obstruction by fecalith.
| In kids --> lymphoid hyperplasia.
281
Test for appendicitis and location
- McBurney point
| - 1/3 the distance from right anterior superior iliac spine to umbilicus.
282
Other signs in appendicits
Psoas, obturator, Rovsing signs. guarding and rebound tenderness on exam.
283
appendicitis differential
diverticulitis (elderly), ectopic, yersinia
284
Most common site of diverticulum
Sigmoid colon
285
What does "false" mean in relation to diverticulum?
Attenuated muscularis externa. Only mucosa and submucosa outpouch.
286
True diverticulum
all 3 gut wall layers, Meckels
287
Area prone to false diverticula
Where vasa recta perforate muscularis externa.
288
diverticulosis
Many false diverticula of the colon, commonly sigmoid.
289
epidemiology of diverticulosis
1/2 of people over age 60.
290
diverticulosis pathophys
Increased intraluminal pressure and focal weakness in colonic wall. Low-fiber diets.
291
Painless bleeding in a person with diverticulosis
Painless hematochezia. *not necessarily diverticulitis.
292
diverticulitis
Diverticulosis with inflamed microperforations.
293
Presentation of diverticulitis
LLQ pain + fever + leukocytosis.
294
Diverticulitis treatment
antibiotics
295
Complications of diverticulitis
1) abscess
2) fistula (colovesical fistula leading to pneumaturia)
3) obstruction (inflammatory stenosis)
4) perforation (leading to peritonitis)
296
If diverticulitis is complicated, management is...
Percutaneous drainage or surgery.
297
Where does mucosal tissue herniate in Zenker's?
Killian triangle between thyropharyngeal and cricopharyngeal parts of the inferior pharyngeal constrictor.
298
Meckel presentation
melena + RLQ pain.
299
Meckel complications
intussusception + volvulus + obstruction near terminal ileum.
300
omphalomesenteric cyst
Cystic dilation of vitelline duct. Not peristence of vitelline duct.
301
Six 2's of Meckel's
```
2x as likely in males
2 inches long
2 feet from ileocecal valve
2% of population
presents in first 2 years of life
2 types of epithelia (gastric/pancreatic).
```
302
Hirschsprung etiology
Congenital megacolon characterized by lack of ganglion cells/enteric nervous plexuses (Auerbach and Meissner plexuses) in distal segment of colon.
303
Hirschprung genetic association
mutations in RET
304
Hirschsprung presentation
Bilious emesis + abdominal distention + failure to pass meconium within 48 hours --> chronic constipation.
305
Hirschsprung diagnosis
Rectal suction biopsy
306
Hirschsprung treatment
Resection
307
Positioning of bowel in malrotation
small intestine in ball in bottom right, large intestine on left side, ladd band between large intestine and liver.
308
Complications of malrotation
1) volvulus
| 2) duodenal obstruction
309
intussusception
PROXIMAL segment telescopes into distal segment.
310
viral infection and intussusception etiology
adenovirus --> peyer patch hypertrophy --> lead point.
311
Most common pathologic lead point
Meckel diverticulum.
312
Usual location of acute mesenteric ischemia
Embolic occlusion of SMA.
313
chronic mesenteric ischemia pathophys
"intestinal angina": atherosclerosis of celiac, IMA, or SMA --> intestinal hypoperfusion --> postprandial epigastric pain --> food aversion and weight loss.
314
colonic ischemia presentation
crampy abdominal pain followed by hematochezia.
315
Watershed areas
splenic flexure, distal colon.
316
Most common locations of angiodysplasia
Cecum, terminal ileum, ascending colon.
317
Most common cause of SBO
adhesions
318
Adhesion presentation
Fibrous band of scar tissue. Can have well-demarcated necrotic zones.
319
Ileus
Intestinal hypomotility without obstruction --> constipation and decreased flatus; distended/tympanic abdomen with decreased bowel sounds.
320
Ileus causes
abdominal surgeries, opiates, hypokalemia, sepsis.
321
ileus treatment
Bowel rest, electrolyte correction, cholinergic drugs (stimulate intestinal motility).
322
necrotizing enterocolitis pathophys
formula fed premies --> immature immune system --> necrosis of intestinal mucosa (primarily colonic) with possible perforation, which can lead to pneumatosis intestinalis, free air in abdomen, portal venous gas.
323
What induces COX-2 production?
IL-2
324
Inguinal (hesselbach) triangle borders
Inferior epigastric vessels, lateral border of rectus. abdominis, inguinal ligament
325
hyperplastic polyp location and presentation
non-neoplastic and smaller. Rectosigmoid area.
326
hamartomatous polyps histology
growths of normal colonic tissue with distorted architecture.
327
adenomatous polyps + presentation
neoplastic, via chromosomal instability pathway. APC and KRAS mutations.
Usually asymptomatic; may present with occult bleeding.
328
serrated polyps
1) genetics
2) epidemiology
1) premalignant via CPG hypermethylation phenotype pathway with microsatelite instability and mutations in BRAF.
2) Up to 20% of cases of sporadic CRC.
329
2 hit hypothesis
You need to lose 2 tumor suppressor genes before getting cancer.
330
Gardner syndrome
FAP + osseus and soft tissue tumors + congenital hypertrophy of retinal pigment epithelium + impacted/supernumerary teeth.
331
Peutz Jeghers syndrome
o Coded character: Megan Yeiter. Emerging from jegher bag in basement with hyperpigmented mouth, lips, genitalia and covered in ham/syndrome featuring numerous hamartomas throughout GI tract. /presentation = hyperpigmented mouth/lips/hands/genitalia + bloody stool (due to intestinal hamartomas). Kenny sitting to her left + Mr. Kolkhorst sitting on a toilet behind her + tammy on her right + T with gut next to kenny/associated with increased risk of colorectal, breast, stomach, small bowel, and pancreatic cancers (but hamartomas themselves don’t undergo malignant transformation) + ovary/uterus/cervix/lung. Femdom chick whipping her from right /autosomal dominant. /pedunculated polyps. Intussuscepted bowel hanging over her from left/hamartomas can occasionally serve as the lead point for intussusception.
332
Peutz jeghers mutation
STK11/LKB1 gene.
333
Juvenile polyposis syndrome
1) presentation
2) prognosis
- AD syndrome in children less than 5 featuring numerous hamartomatous polyps in colon, stomach, small bowel.
- increased risk of CRC
334
Epidemiology of cancer progression in lynch syndrome + area of involvement
80% progress to CRC + proximal colon is always involved.
335
Cancers associated with Lynch syndrome
Associated with endometrial, ovarian, and skin cancers.
336
genetics of CRC
25% have a family history.
337
CRC RF's
1) adenomatous and serrated polyps
2) familial cancer syndromes
3) IBD
4) tobacco use
5) diet of processed meat with low fiber.
338
Areas most commonly involved in CRC
Rectosigmoid>ascending>descending
339
Ascending mass in CRC presentation
exophytic mass + IDA + weight loss
340
descending mass in CRC presentation
Infiltrating mass, partial obstruction, colicky pain, hematochezia.
341
Caveat about CEA tumor marker for CRC
Good for monitoring recurrence, shouldn't be used for screening.
342
Screening for CRC
Colonoscopy, flexible sigmoidoscopy, fecal occult blood test, or fecal DNA test.
343
Genetic cause of most sporadic CRC
Mutations in APC
344
Mismatch repair gene
MLH1
345
Chromosomal instability pathway for CRC
APC --> KRAS --> p53, DCC
346
Cells responsible for fibrosis in cirrhosis
Stellate cells
347
histology of fibrosis
diffuse bridging fibrosis + regenerative nodules.
348
Causes of portal HTN
cirrhosis + vascular obstruction (Budd-Chiari) + schisto
349
metabolic presentation of cirrhosis and portal HTN
cardiomyopathy + peripheral edema
350
hematologic presentation of cirrhosis and portal HTN
thrombocytopenia + anemia + coagulation disorders
351
fetor hepaticus
"breath of the dead." Late sign of liver failure and feature of hepatic encephalopathy. Breath has a sweet, fecal smell to it.
352
Reproductive presentation of cirrhosis and portal HTN
testicular atrophy + gynecomastia + amenorrhea
353
What does AST greater than ALT in nonalcoholic liver disease suggest...
progression to advanced fibrosis or cirrhosis.
354
ALT, AST pattern in most liver disease
ALT is greater than AST, alcoholic liver disease is the exception
355
Marker of cholestasis
ALP
356
gamma-glutamyl transpeptidase
increased in various liver and biliary disease, but not in bone disease.
357
Albumin as a marker of liver disease
decreased in advanced liver disease
358
Prothrombin as a marker of liver disease
Increased in advanced liver disease (decreased production of clotting factors)
359
Platelets as a marker of liver disease
decreased in advanced liver disease
360
Why are platelets decreased in advanced liver disease?
decreased thrombopoietin, liver sequestration and portal HTN (splenomegaly/splenic sequestration).
361
viral infections associated with Reye syndrome
VZV + influenza B
362
Reye syndrome pathophys
aspirin metabolites decrease beta-oxidation by reversible inhibition of mitochondrial enzymes.
363
alcoholic hepatitis histology
swollen and necrotic hepatocytes with neutrophilic infiltration.
364
Mallory bodies
intracytoplasmic eosinophilic inclusions of damaged keratin filaments.
365
alcoholic cirrhosis histology
Micornodular, irregularly shrunken liver with "hobnail" appearance. Sclerosis around central vein.
366
Non alcoholic fatty liver disease:
Super fat hippos sitting around perimeter + inflating balloons + grim reaper sitting in middle/metabolic syndrome (insulin resistance) fatty infiltration of hepatocytes “cellular ballooning” and eventual necrosis. Ollie sitting in chair holding fetus in front of grim reaper/may cause cirrhosis and HCC. /independent of alcohol use. Huge alan + tiny Trojan Spartan to his right/ALT>AST.
367
antibiotic treatment for hepatic encephalopathy
rifaximin or neomycin
368
hepatic encephalopathy trigers
1) increased NH3 production and absorption (due to dietary protein, GI bleed, constipation, infection).
2) decreased NH3 removal (due to renal failure, diuretics, bypassed hepatic blood flow post-TIPS).
369
lactulose MOA in hepatic encephalopathy
Decreases intraluminal ammonia absorption. Lactulose is metabolized by gut bacteria into lactic and acetic acid. The H+ ions emitted bind to NH3, converting it into NH4+ and thereby preventing it’s absorption. Thus, increase NH4+ generation.
370
alpha1-antitrypsin deficiency cancer association
HCC
371
cavernous hemangioma prognosis
benign
372
hepatic adenoma prognosis
May regress spontaneously or rupture (abdominal pain and shock
373
Most common liver tumor mets
GI + breast + lung
374
budd-chiari associations
hypercoagulable states + polycythemia vera + postpartum state + HCC
375
caveat aboud Budd-chiari
Absence of JVD.
376
pathophys of alpha1-antitrypsin deficiency in liver
Misfolded gene product protein aggregates in hepatocellular ER, causing cirrhosis with PAS positive globules in liver.
377
hyperbilirubinemia associated with primary sclerosing cholangitis
conjugated
378
hyperbilirubinemia associated with PBC
conjugated
379
Mixed (direct and indirect hyperbilirubinemia) seen in...
hepatitits, cirrhosis
380
physiologic neonatal jaundice prognosis
usually resolves without treatment in 1-2 weeks.
381
phototherapy for neonatal jaundice mechanize
Isomerizes unconjugated bilirubin to water-soluble form
382
hereditary hyperbilirubinemias genetics
all AR
383
Gilbert syndrome mechanism
Mildly decreased UDP-glucoronysltransferase conjugation and impaired bilirubin uptake.
384
Treatment for Crigler-Najjar type I
Plasmapheresis and phototherapy
385
Type II Crigler-Najjar
Less severe and responds to phenobarbital, which increases liver enzyme synthesis.
386
Rotor syndrome etiology
Impaired hepatic uptake and excretion.
387
another name for conjugated bilirubin
bilirubin diglucuronide
388
another name for Wilson's
hepatolenticular degeneration
389
gene mutation in Wilson's
ATP7B
390
labs in Wilson's
DECREASED ceruloplasmin
391
Kaysr-Fleischer rings
deposits in Descemet membrane of cornea
392
Wilson's treatment
chelation with penicillamine or trientine, oral zinc.
393
HFE chromosome
6
394
hemochromatosis
- ferritin
- TIBC
- transferrin
Increased ferritin, increased iron, decreased TIBC, increased transferrin saturation.
395
Iron overload also seen in..
chronic transfusion therapy (beta-thalassemia major)
396
hemochromatosis presentation
Presents after age 40 when total body iron > 20 g.
397
cardiac presentation of hemochromatosis
dilated cardiomyopathy (reversible)
398
hemochromatosis treatment
Repeated phlebotomy, chleation with deferasirox, deferoxamine, oral deferiprone.
399
cholestatic pattern of LFTs (characteristic of biliary tract disease)
Increased conjugated bilirubin, increased cholesterol, increased ALP.
400
Lab findings in PSC
- p-ANCA positive
| - increased IgM
401
PSC complications
1) biliary cirhosis
| 2) increased risk of cholangiocarcinoma and gallbladder cancer.
402
Secondary biliary cirrhosis 1) pathophys
1)Extrahepatic biliary obstruction leads to increased pressure in intrahepatic ducts, leading to injury/fibrosis and bile stasis.
403
Secondary biliary cirrhosis epidemiology
Patients with known obstructive lesions (gallstones, biliary strictures, pancreatic carcinoma)
404
Secondary biliary cirrhosis complication
Ascending cholangitis
405
what causes gallstones
increased cholesterol and/or bilirubin, decreased bile salts, and stasis.
406
cholesterol gallstone associations
Obestity, crohns, advanced age, estrogen therapy, multiparity, rapid weight loss, Native American.
407
black pigment stone composition
Calcium bilirubinate
408
Brown pigment stone etiology
infection
409
pigment stone associations
Crohn's, advanced age, chronic hemolysis, alcoholic cirrhosis, biliary infections, total parenteral nutrition.
410
complications of gallstones
1) cholecystitis
2) acute pancreatitis
3) ascending cholangitis
4) fistula between gallbladder and GI tract (air in biliary tree0
411
charcot triad of cholangitis
Jaundice + fever + RUQ pain
412
pneumobilia
air in biliary tree
413
gallstone ileus
osbtruction of ileocecal valve due to gallstone from fistula
414
Increased ALP suggests
bile duct involvement (ascending cholangitis)
415
cholecystitis diagnosis
US or cholescintigraphy (HIDA, or hepatobiliary iminiodiacetic acid scan).
416
causes of alcalculous cholecystitis
ischemia and stasis or CMV
417
causes of acute pancreatitis
I GET SMASHED. Idiopathic, Gallstones, Ethanol, Trauma, Steroids, Mumps, Autoimmune disease, Scorpion sting, Hypercalcemia/Hypertriglyceridemia (>1000 mg/dL), ERCP, Drugs (sulfa drugs, NRTIs, protease inhibitors).
418
acute pancreatitis diagnosis
2/3 criteria: acute epigastric pain often radiating to the back, increased serum amylase or lipase (more specific) to 3x upper limit of normal, or characteristic imaging findings.
419
another complication of acute pancreatitis
hypocalcemia (precipitation of Ca2+ soaps)
420
chronic pancreatitis
Chronic inflammation, atrophy, calcification of the pancreas.
421
chronic pancreatitis caveat
amylase and lipase may or may not be elevated (almost always elevated in acute pancreatitis)
422
pancreatic adenocarcinoma personality
Often metastatic at presentation with average survival around 1 year.
423
Trousseau syndrome
migratory thrombophlebitis
424
Courvoisier sign
palpable, nontender gallbladder, characteristic of pancreatic adenocarcinoma.
425
Treatment for pancreatic adenocarcinoma
Whipple procedure + chemo + radiation.
426
gastrin pathway
Gq
427
somatostatin pathway
Gi
428
Prostaglandin pathway
Gi
429
alkaline tide
increased blood pH after gastric acid secretion (eg, after meals, vomiting)
430
carbonic anhydrase
interconverts CO2 + H2 H2CO3
431
How is Cl excreted in parietal cells
HCO3-/Cl- exchanger generates Cl- gradient, then diffuses through channels out
432
Gastrin receptor on parietal cells
CCK3
433
ACh receptor on parietal cells
M3
434
Cholera mechanism
He’s on a stationary bike + there’s tents set up all over the room + swat team is breaking into his house/cholera A-B toxin (a for activating, b for binding) activates adenyl cyclase by ADP ribosylation to increase cAMP. *This leads to increased Cl- secretory channels in crypt cells.
435
CCK has some gastrin-like properties because both CCK and gastrin
Have 5 identical C-terminal amino acids.
436
Monosaccharide transport caveat
Fructose is the only monosaccharide that that is not absorbed by Na+-dependent cotransport. It it stransported by facilitated diffusion.
437
Amino acid absorption in the intestine
Na+-dependent cotransport (*except for oligopeptides)
438
Fatty acid absorption
simple diffusion
439
Why does ileal resection (such as for Crohn's patients) cause steatorrhea?
Ileum normally transports bile acids from the lumen of the gut. Thus, with ileal resection new synthesis of bile acids is needed to replace bile acids that are lost in the feces. With ileal resection most of bile acids secreted are excreted in the feces and the liver pool is diminished. ***Bile acids are needed for micelle formation in the intestinal lumen to solubilize products of lipid digestion so that they can be absorbed. So the problem is MICELLES DO NOT FORM in the intestinal lumen.
440
Where are chylomicrons formed?
Within intestinal epithelial cells and are transported to lymph vessels.
441
Function of CCK
Mediates digestion in the small intestine by inhibiting gastric emptying and decreasing gastric acid secretion. Lines small intestine.
442
Saliva characteristics
1) hypotonic
2) high HCO3- concentration
3) alpha-amylase and lingual lipase
443
control of saliva production
Parasympathetic, thus it is abolished by vagotomy.
444
What are slow waves in small intestinal smooth muscle cells?
oscillating resting membrane potentials.
