embryology- GI embryology-Tracheoesophageal anomalies -Congenital pyloric stenosis-Pancreas and spleen embryology

Question 1

A patient has a malformed gastrointestinal tract from pharynx to duodenum. What part of the embryo had impaired development?

Answer 1

Foregut

Question 2

In a patient with a hiatal hernia, the herniated structure was originally derived from the ____ (foregut/midgut/hindgut).

Answer 2

Foregut (herniation of the proximal stomach through the diaphragm)

Question 3

A developing embryo suffers a malfunction of the midgut. Which region of the gastrointestinal tract will be impacted?

Answer 3

Duodenum to the transverse colon

Question 4

The part of the colon supplied by both the hepatic and splenic flexures is derived from the ____ (foregut/midgut/hindgut).

Answer 4

Midgut (the transverse colon is supplied by both the hepatic and splenic flexures)

Question 5

A developing embryo suffers damage to the hindgut. As an adult, what structures of the GI tract will be affected?

Answer 5

The distal transverse colon to the rectum

Question 6

A patient with ulcerative colitis always has involvement of this GI structure, which derives from the ____ (foregut/midgut/hindgut).

Answer 6

Hindgut (UC always affects the rectum and may affect more proximal regions)

Question 7

An extrusion of abdominal contents not covered by the peritoneum is found on a newborn undergoing surgery. Name this diagnosis.

Answer 7

Gastroschisis (failure of the lateral body folds to fuse)

Question 8

A baby with bladder exstrophy presents to the clinic. What type of folds failed to close properly during embryologic development?

Answer 8

Caudal folds

Question 9

A baby presents with sternal defects. Failure of what type of folds to close properly caused this clinical scenario?

Answer 9

Rostral folds

Question 10

An extrusion of abdominal contents into the umbilical cord is covered by the peritoneum on a newborn having surgery. Name this diagnosis.

Answer 10

Omphalocele (sealed by peritoneum)

Question 11

In the sixth week, the midgut herniates through this structure, then returns to the abdominal cavity (week 10) and rotates around the SMA.

Answer 11

Umbilical ring

Question 12

A newborn presents with severe abdominal distention. Around which artery is the baby’s midgut malrotated?

Answer 12

Superior mesenteric artery

Question 13

A baby is born with trisomy 21 and diagnosed with duodenal atresia. How would you explain this GI tract malformation to the parents?

Answer 13

Failure of the duodenum to recanalize

Question 14

An infant fails to pass meconium at birth. X-ray shows apple-peel atresia of the lower GI tract. What most likely happened in utero?

Answer 14

Vascular accident causing jejunal, ileal, and colonic atresia (characteristic apple-peel atresia on x-ray)

Question 15

What is the most common subtype of tracheoesophageal fistula?

Answer 15

Esophageal atresia (a blind-pouch upper esophagus with the lower esophagus connected to the trachea)

Question 16

What are some symptoms seen with the most common subtype of tracheoesophageal fistula?

Answer 16

Cyanosis, choking, and vomiting with feeding, air bubble on x-ray of the chest (or polyhydramnios, if still in utero)

Question 17

A patient’s CXR shows an airway stricture. He is drooling excessively. How do you confirm your suspected diagnosis?

Answer 17

Attempt to pass a nasogastric tube (in a tracheoesophageal fistula, the tube will not reach the stomach)

Question 18

A newborn chokes and vomits with the first feeding, and she reportedly had polyhydramnios in utero. Why might this baby become cyanotic?

Answer 18

The newborn may develop cyanosis from laryngospasm (to avoid reflux-related aspiration) (this is a tracheoesophageal fistula)

Question 19

A baby with esophageal atresia has a chest x-ray revealing a gasless abdomen. What type of esophageal atresia is this?

Answer 19

Pure atresia

Question 20

In a patient with congenital pyloric stenosis, hypertrophy of the pylorus leads to what problem?

Answer 20

Gastric outlet obstruction

Question 21

An infant with projectile vomiting is found to have a palpable, epigastric, olive-sized mass is found on physical exam. Name this condition

Answer 21

Congenital pyloric stenosis

Question 22

In a baby with suspected congenital pyloric stenosis, what type of vomit would rule out the disorder?

Answer 22

Bilious (bilious vomit originates distal to the pyloric sphincter)

Question 23

The mother of a newborn says her previous child had developed projectile vomiting. When would this most likely occur in this newborn?

Answer 23

2 weeks of age

Question 24

A 3-week-old baby has projectile nonbilious vomiting and a normal physical exam. What treatment will likely be indicated?

Answer 24

Surgical pyloromyotomy (with pyloric stenosis, the classic “olive mass” is often not palpable

Question 25

Congenital pyloric stenosis often occurs in what demographic group?

Answer 25

Male first-born infants

Question 26

Is the pancreas derived from the foregut, the midgut, or the hindgut?

Answer 26

The foregut

Question 27

A patient is diagnosed with pancreas divisum, and she asks how this developed. What do you tell her?

Answer 27

Failure of the ventral and dorsal pancreatic buds to fuse during embryologic development

Question 28

From which dermal layer does the spleen arise: endoderm, mesoderm, or ectoderm?

Answer 28

Mesoderm

Question 29

The spleen receives blood from the ____ (foregut/midgut/hindgut) vasculature.

Answer 29

Foregut (specifically, the celiac artery) even though the spleen has a mesodermal origin

Question 30

A patient has a malformed accessory pancreatic duct. What pancreatic bud did not form correctly?

Answer 30

Dorsal pancreatic bud

Question 31

Ventral pancreatic buds contribute to the formation of these three pancreatic structures

Answer 31

Pancreatic head, main pancreatic duct, and uncinate process

Question 32

A child has malformed mesentery of the stomach. What mesodermal organ that is supplied by the celiac artery are you concerned about?

Answer 32

Spleen