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Question 1

When does the primitive gut begin to form?

Answer 1

The primitive gut begins to form in the fourth week of development.

Question 2

What does the endoderm contribute to the gastrointestinal (GI) tract?

Answer 2

The endoderm gives rise to most of the epithelium and glands of the GI tract, except for the cranial and caudal extremities.

Question 3

Which germ layer contributes to the epithelium of the cranial and caudal extremities of the GI tract?

Answer 3

The ectoderm contributes to the epithelium of the cranial and caudal extremities of the GI tract.

Question 4

What tissues does the mesoderm contribute to the digestive tract?

Answer 4

The mesoderm contributes the muscular tissue and connective tissue of the digestive tract wall.

Question 5

Into what three regions is the primitive gut divided?

Answer 5

The primitive gut is divided into the foregut, midgut, and hindgut.

Question 6

What triggers gut tube formation?

Answer 6

Gut tube formation is triggered by retinoic acid (RA) from the pharynx.

Question 7

Which gene does retinoic acid (RA) activate to specify the esophagus and stomach?

Answer 7

RA activates the SOX2 gene to specify the esophagus and stomach.

Question 8

Which gene is responsible for specifying the duodenum?

Answer 8

The PDX1 gene specifies the duodenum.

Question 9

What gene is responsible for specifying the small intestine?

Answer 9

The CDXC gene specifies the small intestine.

Question 10

Which gene specifies the large intestine and rectum?

Answer 10

The CDXA gene specifies the large intestine and rectum.

Question 11

What is the role of the Sonic Hedgehog (SHH) gene in gut development?

Answer 11

The Sonic Hedgehog (SHH) gene is responsible for epithelial-mesenchymal interactions that shape the gut tube.

Question 12

Where does the spleen come from?

Answer 12

dorsal mesogastrium

Question 13

What are the Derivatives of the primitive gut
(Foregut)

Answer 13

LES ULG PP

Lungs
 Esophagus
 Stomach
 Upper part of the duodenum
 Liver
 Gallbladder
 Pancreas
 Pharyngeal pouches

Question 14

What does the dorsal mesogastrium form?

Answer 14

Dorsal mesogastrium (Mesoderm) rotates the spleen to the left hypochondrium and forms it

Question 15

What does the ventral mesogastrium form?

Answer 15

Ventral mesogastrium rotates the Liver to the right hypochondrium

Question 16

What happens to the left and right vagus after the rotation of the stomach?

Answer 16

The left vagus becomes anterior

The right vagus becomes posterior

Question 17

What else does the rotation of the dorsal mesogastrium form?

Answer 17

The rotation of the dorsal mesogastrium forms the omental bursa

Question 18

What is congenital pyloric stenosis?

Answer 18

Congenital pyloric stenosis is the overproduction of circular fibers at the pyloric region, causing constriction of the pylorus.

Question 19

What is a key symptom of congenital pyloric stenosis in newborns?

Answer 19

A key symptom is projectile vomiting in newborn babies.

Question 20

How is the pancreas formed during development?

Answer 20

The pancreas is formed by the merging of the dorsal and ventral pancreatic buds due to the rotation of the stomach.

Question 21

What part of the pancreas is formed by the dorsal pancreatic bud?

Answer 21

The dorsal pancreatic bud forms the head of the pancreas.

Question 22

What causes annular pancreas?

Answer 22

Annular pancreas is caused by a bifid ventral pancreatic bud.

Question 23

What complication is associated with annular pancreas?

Answer 23

Annular pancreas can cause polyhydramnios during development.