GEM Exam 1 Questions & Answers
2023/2024
what structures are affected in an intrabdominal GS wound? - ANSWER-- small bowel (50%)
- large bowel (40%)
- liver (30%)
- vasculature (25%)
foregut location and blood supply - ANSWER-- distal esophagus to the upper third of the duodenum
- celiac trunk
midgut location and blood supply - ANSWER-- posterior 2/3 of duodenum to splenic flexure
- SMA
hindgut location and blood supply - ANSWER-- splenic flexure to pectinate line
- IMA
celiac trunk major branches - ANSWER-- left gastric, common hepatic, splenic artery, superior
pancreaticoduodenal
- sup. pancreaticoduodenal anastomoses with inf. (from SMA) which can bypass a reduction in flow of
the celiac artery
marginal artery - ANSWER-collateral circulatory loop around large intestine
- can bypass obstruction in SMA or IMA
venous drainage in hut - ANSWER-- splenic vein drains celiac
- IMV drains hindgut
- these branches meet SMV to form the hepatic portal vein which goes to the liver
,portal hypertension - ANSWER-bulging superficial veins, hemorrhoids, hematemesis (vomit blood)
- 4 major sites: esophageal varies, caput medusa (periumbilical veins), hemorrhoids, small veins of
posterior abdominal wall
veins that flow into IVC - ANSWER-renal, gonadal, iliac
- L renal vein goes directly into IVC (can get obstructed with an aneurysm in SMA)
foregut innervation - ANSWER-- sympathetics: T5-T9 go to greater splanchnic n. and synapse CELIAC
GANGLIA then have LONG branches to target organs
- PS: vagus goes to celiac plexus then follow the celiac trunk and synapses in gut plexus then has SHORT
post-synaptic fibers to target organ
midgut innervation - ANSWER-- sympathetics: T10-T12 goes to lesser/ least splanchnic nerve and
synapses in the SMG then has long branches following SMA to target organ
- PS: vagus goes to SM plexus and follows SMA to gut plexus near target organ and synapses then has
SHORT post-synaptic fibers to target
hindgut innervation - ANSWER-- sympathetics: L1-L2 goes to lumbar splanchnic nerves and goes to the
IMG then has LONG branches that follow IMA to target organ
- PS: S2-S4 goes to sup/inf hypogastric plexus and follows arteries to gut plexus where it synapses and
has SHORT post-synaptic fibers to target
RUQ pain - ANSWER-gall bladder problem
RLQ pain - ANSWER-appendix problem
LUQ pain - ANSWER-spleen problem
LLQ pain - ANSWER-possible kidney problem
,where does the esophagus have striated and smooth muscle? - ANSWER-striated m. @ pharyngeal end
and smooth m. @ gastric end
where will stomach contents pool if it gets perforated? - ANSWER-omental bursa (lesser peritoneal sac)
characteristics of jejunum - ANSWER-red, thicker walls, less fat, simple arcades, long vasa recta
characteristics of ileum - ANSWER-pink, thin walls, more fat, less plicae circulars, layered arcades, short
vasa recta
what happens @ 4 weeks gestations (2) - ANSWER-- embryo undergoes folding (cranio-caudal and
lateral)
- oropharyngeal membrane breaks down
intraperitoneal organs - ANSWER-- mobile, wrapped in mesentary
Stomach, Liver, Gallbladder, Spleen, 1st part of duodenum, Jejunum, Ileum, Appendix, Cecum (though no
mesentery)*, Transverse colon, Pancreas (just the tail!)*
secondarily retroperitoneal - ANSWER-parts are behind peritoneal membrane
-2nd, 3rd, and 4th parts of duodenum, Pancreas (all but tail), Ascending colon, Descending colon,
Rectum (superiormost)*
primarily retroperitoneal - ANSWER-completely behind peritoneal membrane
- Kidneys & Ureters, Adrenal (Suprarenal) glands, Rectum (most), Anal canal
what happens at 7 weeks? - ANSWER-cloacal membrane breaks down
polyhydramnios - ANSWER-increased amniotic fluid
- seen in: double bubble, esophageal atresia, duodenal atresia
, oligohydramnios - ANSWER-decreased amniotic fluid
esophageal development and derivation - ANSWER-tracheoesophageal folds fuse then close off to form
2 tubes (trachea and esophagus)
- elongates with descent of septum transversum
- distal esophagus (smooth m.) arises from foregut (splanchnic mesoderm), remainder from pharyngeal
arch mesenchyme (striated m.)
esophageal atresia - ANSWER-esophagus stops and trachea has an extra branch (90% associated w/
trachoesophageal fistula)
- present: polyhydramnios, increased oral secretions, respiratory distress,
- dx: CXR, bronchoscopy (after failed NG tube placement)
- tx: surgical repair
greater omentum origin - ANSWER-dorsal mesentery
lesser peritoneal sac origin - ANSWER-ventral mesentery
how does the stomach rotate? - ANSWER-90 degrees CLOCKWISE, the left vagus nerve rotates with it
(forms anterior vagal trunk)
spleen origin - ANSWER-splanchnic mesoderm
- 10% of population has accessory spleen
double bubble sign - ANSWER-classic sign for duodenal atresia
- bubbles are before AND after pylorus
- MCC: failure of recanalization (especially by biliary apparatus)
- uncommon cause: annular pancreas
- see polyhydramnios
