Embryology

Question 1

Foregut/Midgut/Hindgut boundaries

Answer 1

Foregut: esophagus to upper duodenum
Midgut: lower duodenum to proximal 2/3 of transverse colon
Hindgut: distal 1/3 to anal canal above pectinate line

Question 2

Midgut development

Answer 2

6th week: physiologic midgut herniates through umbilical ring
10th week: returns to abdominal cavity and rotates around SMA, total 270 counterclockwise

Question 3

Ventral wall defects and hernias causes

Answer 3

DUE TO FAILURE OF:
Rostral fold closure–> sternal defects (ectopia cordis)

Lateral fold closure—> omphalocele, gastroschisis

caudal fold closure —> bladder exstrophy

Question 4

Gastroschisis

Answer 4

Extrusion of abdominal contents through abdominal folds
Typically right of umbilicus
NOT covered by peritoneum or amnium

Question 5

Omphalocele

Answer 5

Persistent herniation of abdominal contents into umbilical cord, sealed by peritoneum

Question 6

Congenital Umbilical Hernia

Answer 6

Incomplete closure of umbilical ring

Question 7

MC tracheoesophageal anomaly

Answer 7

Esophageal atresia with distal tracheoesophageal fistula

Question 8

CXR of a baby with tracheoesophageal fistula

Answer 8

Air into stomach

Question 9

Why do babies with tracheoesophageal fistula develop cyanosis?

Answer 9

Secondary to laryngospasm (to prevent aspiration)

Question 10

tracheoesophageal fistula clinical test

Answer 10

Failure to pass levine

Question 11

CXR of pure esophageal atresia

Answer 11

Gasless abdomen

Question 12

Intestinal atresia clinical presentation

Answer 12

Bilious vomiting and abdominal distention with first 1-2 days of life

Question 13

Duodenal atresia pathophysiology and sign

Answer 13

Failure to recanalize. Associated with double bubble sign (dilated stomach, proximal jejunum)
The pathophysiology of dudoenal stenosis and atresia differs from that of obstructions located more distally in the jejunoileal area; the importance of this difference cannot be overstated. In duodenal atresias, a failure of recanalization of intestinal tube occurs at 8-10 weeks’ gestation after obliteration of the lumen by epithelial proliferation at 6-7 weeks; it usually occurs in the second part of the duodenum. Incomplete recanalization can lead to duodenal stenosis or the presence of a duodenal web

Question 14

Duodenal atresia - Syndrome that is associated with

Answer 14

Down

Question 15

Jejunal and ileal atresia

Answer 15

Patients with this disorder are born with a partial absence of the fold of the stomach membrane that connects the small intestine to the back wall of the abdomen. As a result, one of the three portions of the small intestine (the jejunal) twists around one of the arteries of the colon called the marginal artery and causes a blockage (atresia).

mesenteric defect–>Disruption of mesenteric vessels–> ischemic necrosis–> segmental resorption (bowel discontinuity or APPLE PEEL

Intestinal atresia type IIIb (apple-peel or Christmas-tree deformity). Proximal pouch is dilated. Collapsed distal intestine encircles marginal artery helically. Intestinal length is substantially reduced.

Question 16

Vomit of hypertrophic pyloric stenosis pateients

Answer 16

NON bilious and projectile

Question 17

Acid base abnormalities of a patient with hypertrophic pyloric stenosis

Answer 17

hypocholremic hypokalemic metabolic alkalosis due to gastric acid vomit and contraction alkalosis

Question 18

hypertrophic pyloric stenosis

syndromes it is associated with

Answer 18

Turner

Edwards

Question 19

Pancreas- From which part of the gut does it come from?

Answer 19

Foregut
ventral pancreatic bud becomes contributes to uncinate process and main pancreatic duct

dorsal bud alone becomes, body, tail,,isthmus, accesory pancreatic duct

BOTH: contribute to pancreatic head

Question 20

Annular pancreas- Around which part of duodenum

Answer 20

2nd

Question 21

Spleen embryology

Answer 21

Arises in mesentery of stomach (hence it is mesodermal) but has foregut supply( celiac trunk)