Exam 2 (Lecture 8) - Abdomen 3

Question 1

In relation to the pancreas, what develops from the ventral primordium?

Answer 1

Pancreatic duct (opens on the major duodenal papilla)
- The bile duct also opens on the major duodenal papilla

Question 2

In relation to the pancreas, what develops from the dorsal primordium?

Answer 2

Accessory pancreatic duct (opens on the minor duodenal papilla)

Question 3

Which species have both the pancreatic duct and accessory duct?

Answer 3

1) Dog
2) Horse

Question 4

Which species have ONLY a bile duct that opens on the major duodenal papilla?

Answer 4

1) Cow
2) Pig

**These two species also have the accessory pancreatic duct that opens on the minor duodenal papilla

Question 5

Which species have ONLY the major duodenal papilla/pancreatic duct? What is one exception?

Answer 5

1) Small ruminant and cat

2) In about 20% of cats (probably fewer), there is an accessory pancreatic duct present

Question 6

Describe the anatomy of the pancreas of the pig.

Answer 6

1) Left lobe (“free end”)
2) Body
3) Anulus pancreatis (ring; dorsal to the body)
4) Right lobe (empties into the duodenum)

Question 7

Describe the anatomy of the pancreas of the ruminant.

Answer 7

1) Left lobe (“free end”)
2) Body
3) Incisura pancreatis (notch; dorsal to the body)
4) Right lobe (empties into the duodenum)

Question 8

Describe the anatomy of the pancreas of the horse.

Answer 8

Y-shaped

1) Left lobe (triangle at the top left of the “Y”)
2) Right lobe (blunted/flattened at the top right of the “Y”)
3) Body (largest in any of the domestic species; base of the “Y”); empties into the duodenum
4) Annulus pancreatis (ring; dorsal to the body)

Question 9

Describe the anatomy of the pancreas of the dog.

Answer 9

1) Left lobe (“free end”)
2) Body
3) Incisura pancreatis (dorsal to the body)
4) Right lobe (empties into the duodenum)

Question 10

Describe the embryologic intestinal development of the hindgut.

Answer 10

1) The intestine is supported by an elongated dorsal mesentery and vitelline (cranial mesenteric) artery.

2) Cecum forms as an evagination of caudal limb of the loop.

3) Loops toward umbilicus and yolk sac; physiologic herniation (outside of the body)

4) The cranial limb loop is going to undergo an explosive amount of development.
- Cranial limb is going to move to the right of the cranial mesenteric artery and move caudally as it does so
- As this happens, it displaces the caudal limb cranially
- When that happens, the caudal limb displaces the cranial limb over to the right side.

Question 11

What are the foregut derivatives?

Answer 11

1) Part of esophagus
2) Stomach
3) Descending duodenum
4) Liver
5) Pancreas

Question 12

What supplies blood to the foregut derivatives?

Answer 12

Celiac artery

Question 13

What else does the celiac artery supply? Why?

Answer 13

The spleen

While it is not a foregut derivative, embryologically, it develops in the same region as the foregut derivatives.

Question 14

What are the unpaired abdominal arteries?

Answer 14

1) Celiac artery
2) Cranial mesenteric artery
3) Caudal mesenteric artery

Question 15

What are the branches of the celiac artery in the dog, horse, and pig?

Answer 15

1) Splenic artery
- supplies the spleen and gives off the left gastroepiploic artery
- left gastroepiploic artery runs along the greater curvature of the stomach

2) Left gastric artery
- direct branch of the celiac artery
- runs along the lesser curvature of the stomach

3) Hepatic artery
- gives off the right gastric artery (lesser curvature)
- gives off the right gasroepiploid artery (greater curvature)
- gives off the cranial pancreatico-duodenal (pyloric region)

Question 16

What are the branches of the celiac artery in the rumen?

Answer 16

1) Splenic
- gives off the right ruminal artery
- the right ruminal artery runs on the right side of the rumen in the right accessory groove; then in the caudal
groove, it transitions from the R to L side; it then courses dorsally and ventrally to give off the dorsal and
ventral coronary arteries (R and L)
- right ruminal artery IS THE MAJOR SUPPLIER OF BLOOD TO THE RUMEN!!!!

2) Left gastric
- runs on the right side of the rumen
- just dorsal to the omasum it gives off two branches; one is maintained as the left gastric artery on the
lesser curvature of the abomasum; the other branch is the left gastroepiploic that runs on the greater
curvature of the abomasum.

3) Hepatic
- gives off the right gastric (runs along the lesser curvature of the abomasum)
- gives off the right gastroepiploic (rungs along the greater curvature of the abomasum)
- gives off the cranial pancreatico-duodenal artery

4) Left Ruminal
- initially, going to be found on the right side of the rumen
- turns from R to L in the cranial groove
- once on the L side it runs in the left longitudinal groove

Question 17

What are the midgut derivatives and what supplies them?

Answer 17

1) Ascending duodenum
2) Jejunum
3) Ileum
4) Cecum
5) Ascending colon
6) Transverse colon

**Supplied by the cranial mesenteric artery

Question 18

In the horse, which artery supplies blood to the right and left ventral ascending colon?

Answer 18

Colic branch of the ileocolic artery (branch of the cranial mesenteric artery)

Question 19

In the horse, which artery supplies blood to the right and left dorsal ascending colon?

Answer 19

Right colic branch of the ileocolic artery (branch of the cranial mesenteric artery)

Question 20

In cattle, which artery supplies blood to the centripetal and proximal loops?

Answer 20

Colic branch

Question 21

In cattle, which artery supplies blood to the centrifugal and distal loops?

Answer 21

Right colic

Question 22

In the pig, which artery supplies the centripetal turns?

Answer 22

Colic branch

Question 23

In the pig, which artery supplies the centrifugal turns?

Answer 23

Right colic

Question 24

What structures does the hepatic portal vein drain? What is the exception and where does it drain?

Answer 24

The hepatic portal vein drains all of the structures that are supplied by the celiac, cranial mesenteric, and caudal mesenteric arteries.

The exception is the liver; it drains into the caudal vena cava.