ANAT Development & Adult Anatomy of the Foregut - Week 2

Question 1

What are the three divisions of the gut tube?

Answer 1

Foregut, midgut, hindgut.

Question 2

What does lateral folding lead to?

Answer 2

Gut tube being enclosed by the body wall.

Question 3

What does cranial-caudal folding lead to?

Answer 3

Creation of 3 separate sections of the gut tube.

Question 4

What does C3,4,5 innervation reveal about embryology?

Answer 4

Diaphragm originates from the cervical region.

Question 5

When does lateral & cranial-caudal folding occur?

Answer 5

Simultaneously.

Question 6

Explain pancreatic embryological development.

Answer 6

Pancreas has a ventral & dorsal pancreatic bud in development.
Ventral pancreatic bud has to rotate over 180 to reach the dorsal pancreatic bud.

Question 7

Presentation of annular pancreas

Answer 7

Children are unable to hold down food as food cannot pass through stomach to duodenum/intestine. Surgery is required to rectify this.

Question 8

What is the round ligament?

Answer 8

Obliterated umbilical vein (developmental remnant) present in the adult liver.

Question 9

Liver duct adult structure

Answer 9

Ligamentum venosum

Question 10

Explain the foregut rotation process of embryological development

Answer 10

Stomach is the division between the anterior & posterior body wall.
Stomach is wrapped in peritoneum and is connected to the ventral body wall as well as the dorsal body wall.
A few weeks after the stomach expands, the liver bud grows from feet of gut tube and divides ventral mesentery into two.
On the most anterior part of the liver, falciform ligament connects liver to the ventral body wall. On the posterior part of the liver, hepatogastric ligament connects liver to the anterior surface of the stomach.
Liver then grows rapidly – outgrowing ventral mesenteric space and thus, drives foregut developmental rotation. Stomach is thus rotated so that initial anterior face of stomach is rotated right and posterior face of stomach is rotated more anteriorly.
Simultaneously, spleen divides dorsal mesenteric region into two via gastroleeno/gastrosplenic ligament (connecting stomach to the spleen) and via spleenorenal ligament (connecting spleen to the posterior body wall).

Question 11

What does a ligament =

Answer 11

Double fold of mesentery (mesoderm).

Question 12

Where is the kidney located in the foregut?

Answer 12

Behind the layer of peritoneum on the posterior body wall.

Question 13

What is the bare area of the liver?

Answer 13

Part of the adult liver which is not covered in peritoneum due to its direct contact with the skeletal muscles of the diaphragm.

Question 14

Abdominal aorta branches, locations & vascular supply

Answer 14

Coeliac trunk @ T12 - f
Superior mesenteric artery @ L1 - m
Inferior mesenteric artery @ L3 - h

Question 15

Name the part of the pancreas which lies dorsal to the aorta & state embryological origin.

Answer 15

Embryonic ventral bud - rotated to become dorsal = ucinate process.

Question 16

Classify pancreas as intra, retro or secondary retroperitoneal

Answer 16

Pancreas - secondary retroperitoneal. Tail of the pancreas ‘tickles spleen’ - intraperitoneal.

Question 17

What forms the greater sac?

Answer 17

Anterior face of liver, stomach & spleen.

Question 18

What forms the lesser sac?

Answer 18

Posterior face of liver, stomach & spleen.

Question 19

Describe movement of stomach & associated development of the greater omentum.

Answer 19

Post rotation to the right, stomach’s dorsal aspect (greater omentum) grows rapidly, increasing in weight to ‘sit down’ - shifting the greater omentum more anterior & inferior.

Question 19

Describe movement of stomach & associated development of the greater omentum.

Answer 19

Post rotation to the right, stomach’s dorsal aspect (greater omentum) grows rapidly, increasing in weight to ‘sit down’ - shifting the greater omentum more anterior & inferior.

Question 20

What was the greater omentum embryologically?

Answer 20

Dorsal mesentery.

Question 21

What was the lesser omentum embryologically?

Answer 21

Ventral mesentery.

Question 22

Types of mesentery present in each of the three divisions of the gut.

Answer 22

Foregut is the only region with both ventral & dorsal mesentery. Ventral mesentery is contributed by septum transversum (origin of the diaphragm). Dorsal mesentery in every other region.