Wk2 Digestive System Embryonic Development

Question 1

Which embryonic germ layer gives rise to the epithelial lining of the gut tube?

Answer 1

C. Endoderm

The endoderm is responsible for forming the inner lining of the gastrointestinal tract.

Question 2

What morphogenetic movement is primarily responsible for closure of the gut tube and ventral body wall?

Answer 2

B. Ventral folding morphogenesis

This movement is crucial for the proper formation of the gut tube during embryonic development.

Question 3

The vitelline duct connects the primitive midgut to which structure?

Answer 3

C. Yolk sac

The yolk sac provides nutrients to the developing embryo before the placenta forms.

Question 4

During gastrulation, the definitive endoderm originates from:

Answer 4

C. Epiblast cells migrating through the primitive streak

This process is essential for establishing the three germ layers in the embryo.

Question 5

The foregut extends from the mouth to which region?

Answer 5

B. Duodenum

The foregut includes structures such as the esophagus, stomach, and the proximal part of the duodenum.

Question 6

The midgut receives its blood supply from which artery?

Answer 6

B. Cranial mesenteric

This artery is responsible for supplying blood to the majority of the small intestine and part of the large intestine.

Question 7

The hindgut gives rise to:

Answer 7

B. Descending colon and rectum

The hindgut is involved in the formation of the distal parts of the gastrointestinal tract.

Question 8

Which embryonic structure divides the cloaca into rectal and urogenital portions?

Answer 8

C. Urorectal septum

This structure is important for the proper separation of the urinary and digestive tracts.

Question 9

The dorsal mesentery:

Answer 9

C. Suspends the gut from the dorsal body wall

It plays a critical role in supporting the gastrointestinal tract during development.

Question 10

The ventral mesogastrium gives rise to:

Answer 10

B. Lesser omentum and falciform ligament

These structures are important for connecting the stomach to the liver and the anterior abdominal wall.

Question 11

The greater omentum develops from which structure?

Answer 11

B. Dorsal mesogastrium

The greater omentum is a large fold of peritoneum that hangs down from the stomach.

Question 12

The ruminant forestomachs (rumen, reticulum, omasum) develop as:

Answer 12

B. Outgrowths from a single stomach dilation

This adaptation is crucial for the digestion of fibrous plant material.

Question 13

In the newborn ruminant, which compartment has the largest volume?

Answer 13

C. Abomasum

The abomasum is the true stomach in ruminants, responsible for enzymatic digestion.

Question 14

The horse’s cecum and sacculated colon arise primarily from elongation of which gut region?

Answer 14

B. Hindgut

This adaptation allows for fermentation and digestion of fibrous materials in horses.

Question 15

Meckel’s diverticulum is a remnant of which structure?

Answer 15

B. Vitelline duct

This congenital anomaly can lead to complications if it becomes inflamed.

Question 16

Omphalocele differs from umbilical hernia because omphalocele contents are:

Answer 16

B. Covered by peritoneum and amnion

This condition involves the abdominal contents being herniated through the umbilical ring.

Question 17

Umbilical hernia involves:

Answer 17

B. Defect in the ventral body wall closure

This defect allows abdominal contents to protrude through the abdominal wall.

Question 18

Congenital megaesophagus is often caused by:

Answer 18

C. Persistent right aortic arch

This condition can lead to difficulty in swallowing and regurgitation.

Question 19

During midgut development, physiologic herniation occurs because:

Answer 19

C. The abdominal cavity temporarily cannot accommodate rapid gut growth

This is a normal part of development before the intestines return to the abdominal cavity.

Question 20

Total rotation of the midgut loop during development equals:

Answer 20

C. 270° counterclockwise

This rotation is essential for the proper positioning of the intestines.