Sievert: Digestive development

Question 1

Lateral folding creates two (blank) cavities in the developing embryo

Answer 1

coelemic

Question 2

What do the mucosa and glands of the GI tract arise from? Where does the surrounding smooth muscle and connective tissue come from?

Answer 2

endoderm; splanchnic lateral plate mesoderm

Question 3

What area of the gut maintains a ventral mesentary?

Answer 3

Foregut

Question 4

Below the foregut, the coelemic sac is (blank)

Answer 4

continuous

Question 5

Is there a ventral mesentary in the midgut or hindgut?

Answer 5

No

Question 6

What organs does the ventral mesentary support?

Answer 6

Liver and gallbladder

Question 7

Below the foregut area, the (blank) mesentery disappears so the two separate coelomic sacs become one

Answer 7

ventral

Question 8

Structures that never have a mesentery are (blank) and those that lose their mesentery are (blank)

Answer 8

primarily retroperitoneal; secondarily retroperitoneal

Question 9

Why is the falciform ligament important?

Answer 9

The umbilical vein travels alongside it and enters the liver

Question 10

What is the artery that supplies the forefut? Midgut? Hindgut?

Answer 10

Foregut: celiac artery
Midgut: superior mesenteric artery
Hindgut: inferior mesenteric artery

Question 11

What does the midgut include?

Answer 11

rest of duodenum to distal third of the transverse colon

Question 12

The stomach undergoes a 90 degree rotation with the anterior surface turning to the (blank). This creates the (blank) curvature.

Answer 12

right; lesser

Question 13

When the rotation to the right occurs, the (blank) mesentary gets pushed to the right.

Answer 13

ventral

Question 14

Which surface of the stomach rotates to the left? What does this create?

Answer 14

posterior surface; the greater curvature

Question 15

Because the greater curvature grows more rapidly than the lesser curvature, what must grow quickly to keep up? What does this expansion create?

Answer 15

dorsal mesentery; the greater omentum

Question 16

As the greater omentum hangs down over the stomach, how many layers of mesentary has it become?

Answer 16

Four layers (two are folded over one another)

Question 17

What is found between the liver and the gut?

Answer 17

Lesser omentum

Question 18

The space behind the lesser omentum (known as the lesser sac) retains a small area of continuity with the greater sac through an opening known as the (blank)

Answer 18

epiploic foramen

Question 19

What three buds are attached to the duodenum at the same place (on the ventral side)?

Answer 19

The liver, gallbladder, and ventral pancreatic buds

Question 20

Differential growth and rotation in the wall of the duodenum moves the opening of the (blank) around to the dorsal surface

Answer 20

bile duct

Question 21

Where does the largest pancreatic bud form?

Answer 21

On the dorsal side

Question 22

What happens to the ventral pancreatic bud?

Answer 22

It twists around the duodenum and “slams up” posterior to the dorsal pancreas

Question 23

The duct of the (blank) pancreas is the main duct although most of the tissue is from the (blank) pancreas

Answer 23

ventral; dorsal

Question 24

The common bile duct (which was on the ventral side) whips around with the main pancreatic duct and they come together where?

Answer 24

major duodenal papilla

Question 25

What happens to what is left of the dorsal pancreatic duct?

Answer 25

It becomes an "accessory"

Question 26

The twisting across the duodenum creates the potential for formation of what?

Answer 26

vulvulas

Question 27

What is considered the "axis" of the midgut as it begins to rotate?

Answer 27

the superior mesenteric artery

Question 28

What three things make up the caudal half of the loop of the midgut?

Answer 28

cecum, ascending colon, and transverse colon

Question 29

Rotation in the midgut occurs in what direction if you are looking at the anterior surface of the fetus? How many degrees?

Answer 29

counterclockwise; 270 degrees

Question 30

During what week does the midgut begin to bulge out of the abdominal cavity? By what week does it return?

Answer 30

About the 5th week; 10th week

Question 31

Rotation of the midgut results in the fourth part of the duodenum getting trapped under the (blank).

Answer 31

SMA

Question 32

Rotation of the midgut causes the colon to frame the small bowel around the periphery and puts the (blank) in the lower right quadrant and the (blank) on the left side.

Answer 32

cecum; descending colon

Question 33

The (blank) undergoes differential growth back in the body and completes the final 90 degrees of rotation.

Answer 33

cecum

Question 34

Although the early rotation takes place outside of the fetus because of the rapid growth of the tube relative to the fetus, the final stages of rotation take place where?

Answer 34

in the abdominal cavity

Question 35

Why do we need the falciform ligament?

Answer 35

to support the umbilical vein, which runs along the abdominal wall and drains into the liver

Question 36

Any form of rotation of parts of the gut tube can be dangerous because of potential for disrupting the blood supply and causing (blank)

Answer 36

gangrene

Question 37

What is the condition in which the gut tube fails to reenter the body cavity, and is NOT covered with amnion?

Answer 37

gastroschisis

Question 38

Any rotation or movement of the gut that causes restriction of gut contents.

Answer 38

Vulvula

Question 39

What is the condition in which there is failure of the intestinal loops to return to the body cavity, but they ARE covered in amnion?

Answer 39

omphalocele

Question 40

Most common GI developmental abnormality?

Answer 40

ileal diverticulum

Question 41

Most common GI developmental abnormality, in which a small portion of the vitelline duct persists.

Answer 41

Meckel's or ileal diverticulum

Question 42

In hindgut development, what is the significance of the pectinate line?

Answer 42

It separates the endoderm derivatives from the ectoderm derivatives

Question 43

What kind of innervation does the endodermal derivative of the hingut receive?

Answer 43

Autonomic nervous system sensory fibers; cannot send distinct pain information

Question 44

What kind of innervation does the ectodermal derivative of the hindgut receive?

Answer 44

Below pectinate line, cutaneous nerve innervation; it is extremely sensitive, which is why external hemorrhoids hurt

Question 45

What does the foregut become?

Answer 45

The stomach

Question 46

What is the blood supply to the foregut?

Answer 46

The celiac trunk (specifically the left gastric artery)

Question 47

What does the midgut become?

Answer 47

4th part of the duodenum to the left colic flexure

Question 48

What is the blood supply to the midgut?

Answer 48

The SMA

Question 49

What does the hindgut become?

Answer 49

The rest of the gut from the left colic flexure down

Question 50

What is the blood supply to the hindgut?

Answer 50

The IMA

Question 51

2 components of the ventral mesentery that remain in adults

Answer 51

falciform ligament | lesser omentum

Question 52

Structures that never have a mesentery are considered (blank), while those that lose their mesentery are considered (blank)

Answer 52

primarily retroperitoneal; secondarily retroperitoneal