Feb28 M2-GI Embryology In the Trenches Part 1

Question 1

general cause of duodenal atresia

Answer 1

defect in development

Question 2

usual cause of jejunum and ileum atresia

Answer 2

blood supply problem (thrombus, vessel spasm)

Question 3

how and when gut grows

Answer 3

week 4. primordial gut: outpouching of endoderm growing in adjacent mesenchyme

Question 4

structures derived from foregut

Answer 4

• pharynx
• lower resp tract
• esophagus
• stomach
• duodenum
• liver and biliary tract
• pancreas

Question 5

important concept in duod embryo

Answer 5

stuff in midgut can affect it bc duod is transition to

midgut

Question 6

why stomach has greater and lesser curvature

Answer 6

dorsal border grew faster than ventral border = greater curvature

Question 7

vagus and stomach 90 deg clockwise rotation

Answer 7

1. left side became anterior (left vagus anterior)

2. right vagus posterior

Question 8

cause of stomach fixation anomaly

Answer 8

loose attachments, diaphragmatic defects

Question 9

consequence of stomach fixation problem

Answer 9

possible volvulus (obstructive and or ischemic)

Question 10

treatment of fixation anomaly of stomach

Answer 10

gastropexy: stitch stomach laparo + stitch to diaphragm

Question 11

organoaxial volvulus def

Answer 11

stomach twisted upwards on its axis. lesser curvature points down

Question 12

organomesenteric volvulus def

Answer 12

stomach twisted on its entire mesentery + pylorus pushing against diaphragm

Question 13

organoaxial volvulus conseq

Answer 13

ischemia

Question 14

organomesenteric volvulus conseq

Answer 14

obstruction: pylorus can’t empty. vomiting

Question 15

(IMPORTANT) most common GI anomaly in infants

Answer 15

pyloric stenosis

Question 16

symptoms of pyloric stenosis

Answer 16

projectile vomiting. non bilious

Question 17

pyloric stenosis charact and causes

Answer 17

genetic (more in males). kind of congenital (pylorus thickens in weeks after birth)

Question 18

pyloric stenosis dx test

Answer 18

US. shoulder effect (shouldering is seen)*

Question 19

pyloric stenosis treatment

Answer 19

cut stenosis (temporary and anws stenosis resolve by itself later)

Question 20

duod development

Answer 20

1. hollow organ first then filled by the prolif of epith cells
2. apoptosis and shedding due to ischemia and overprolif = recanalization
   hollow to solid to hollow

Question 21

4 causes of duod obstruction

Answer 21

• duod atresia
• duod stenosis
• annular pancreas
• malrotation

Question 22

duod obstruction: often where + 2 main things

Answer 22

often distal to ampula of Vater (and sphincter of Oddi)

• bilious vomiting
• polyhydramnios

Question 23

(IMPORTANT) dx sign of duod obstruction

Answer 23

double bubble sign

Question 24

(IMPORTANT) how to dx complete vs partial obstruction of duodenum

Answer 24

• complete = no distal air (other than double bubble)

- partial obstruction = distal air present (other than double bubble)

Question 25

in GENERAL: which is worse partial or complete obstruction and why

Answer 25

complete bc more distension higher P on wall, move venous congestion, poor arterial supply, necrosis

Question 26

(IMPORTANT) exception where partial obst worse than complete and why

Answer 26

duodenum obstruction caused by MIDGUT VOLVULUS (there is air distal on XR): URGENT BECAUSE OF ISSUE OF POSSIBLE GUT ISCHEMIA

Question 27

annular pancreas cause

Answer 27

bifid ventral bud fuses with dorsal bud

Question 28

what allows reduction of phgy herniation

Answer 28

liver reduces in size + abd cavity increases in size

Question 29

duod obstruction cause that is not in duodenum

Answer 29

midgut volvulus

Question 30

duod obstructions where get air distal and those with no air distal

Answer 30

air distal = stenosis, midgut volvulus no air distal = atresia annular pancreas may have air

Question 31

midgut forms what

Answer 31

duod starting D3, instestine, cecum and appendix, colon until splenic flexure

Question 32

why atresia (no air distal), stenosis (air distal) and annular pancreas (yes or no air distal) are not emergencies compared to midgut volvulus causing duod obst (air distal)

Answer 32

because no issue of ischemia

Question 33

duodenojejunal limb and cecocolic limb location to SMA after total gut rotation

Answer 33

duodenojejunal to SMA left | cecocolic to SMA right

Question 34

name of duct persisting if failure of yolk sac stalk obliteration

Answer 34

omphalomesenteric duct

Question 35

consequences of omphalomesenteric duct that persists

Answer 35

many anomalies possible. most common is Meckel's diverticulum

Question 36

what kind of duod obstruction in midgut volvulus

Answer 36

PARTIAL (which is why get distal air)

Question 37

partial duod obstruction on XR: next dx step

Answer 37

upper GI test to check for volvulus

Question 38

2 types of volvulus

Answer 38

classical and segmental

Question 39

classical volvulus cause

Answer 39

no fixation, mesentery didn't widen + have ladd's bands. malrotation causes volvulus to occur

Question 40

segmental volvulus cause

Answer 40

mass in bowel (tumor or malformation) causes bowel to volvulize

Question 41

malrotation main concern

Answer 41

RISK OF VOLVULUS