Exam 2 (Lecture 6) - Abdomen 1

Question 1

What are the non-glandular parts of the ruminant stomach?

Answer 1

1) Rumen
2) Reticulum
3) Omasum

Question 2

What is the glandular part of the ruminant stomach?

Answer 2

Abomasum

Question 3

From the left side of the cow, which stomach chambers can we see?

Answer 3

1) Rumen
2) Reticulum
3) Abomasum

Question 4

Where are the grooves vs. pillars located in the ruminant stomach?

Answer 4

1) Grooves = external surface
2) Pillars = internal surface

Question 5

What is the one exception to the internal ruminal pillars?

Answer 5

The demarcation between the rumen and the reticulum is NOT a pillar; it is the rumenoreticular FOLD

Question 6

Which ruminal grooves are visible on the left side?

Answer 6

1) Rumenoreticular groove
2) Cranial groove
3) Left longitudinal groove
4) Caudal groove
5) Left dorsal coronary groove
6) Left ventral coronary groove

Question 7

From the right side of the cow, which stomach chambers can we see?

Answer 7

1) Rumen
2) Reticulum
3) Omasum
4) Abomasum

(All of them)

Question 8

Which ruminal grooves are visible from the right side?

Answer 8

1) Caudal groove
2) Right dorsal coronary groove
3) Right ventral coronary groove
4) Right longitudinal groove (ventral to accessory groove)
5) Right accessory groove (ventral to longitudinal groove)
6) Cranial groove (just cranial to the right longitudinal and right accessory grooves)
7) Rumenoreticular groove (ventral to the omasum)

**The ruminal island is found between the right longitudinal and right accessory grooves

Question 9

Moving from cranial to caudal, what are the sacs of the rumen?

Answer 9

1) Reticulum
2) Ruminal atrium (cranioventral to dorsal sac)
3) Dorsal sac
4) Ventral sac
5) Caudodorsal blind sac
6) Caudoventral blind sac

Question 10

Describe the gastric groove. What is it’s significance from a clinical standpoint?

Answer 10

The gastric groove has 3 segments:
- Reticular groove
- Omasal groove
- Abomasal groove

The gastric groove bypasses the non-glandular part of the stomach (in the young animal) and gets milk directly into the glandular part of the stomach from the esophagus.

There are two thickenings on either side of the gastric groove; when the animal nurses, the two thickenings are going to wrap around each other to form a tube for the milk to bypass the non-glandular parts of the stomach.

Clinical significance: The gastric groove can still close in the adult. This can be useful when a cow is dehydrated; high levels of ADH signal it to close so that water will go directly into the abomasum); can also manipulate when administering drugs that need to get directly into the glandular part of the stomach.

Question 11

What is the function of the retroperitoneal attachment in the ruminant? Where is it located?

Answer 11

1) Fixes the rumen into position; aids in rumen contractions.

2) Esophagus to L4

Question 12

What are the openings within the omasum?

Answer 12

1) Reticulo-omasal opening

2) Omaso-abomasal opening

Question 13

Describe the structure of the abomasum.

Answer 13

1) Folds of mucosa = spiral folds

2) Pyloric torus = thickening along the lesser curvature in the pyloric part

Question 14

What are the parts of the ascending colon in cattle?

Answer 14

Ascending colon (after the cecum):
1) Proximal loop
2) Spiral loop/spiral colon
- centripetal turns (go INTO the spiral; 1.5 - 2 turns)
- central flexure (between centripetal and centrifugal turns)
- centrifugal turns (come OUT of the spiral; 1.5 - 2 turns
3) Distal loop

Question 15

What are the differences in the ascending colon of the small ruminant?

Answer 15

1) Typically 3-4 centripetal turns

2) Typically 3-4 centrifugal turns as well
- The last centrifugal turn is going to be IMMEDIATELY adjacent to the jejunum (the last turn is between the
jejunum and jejunal lymph nodes).

Question 16

What is found in the supraomental recess?

Answer 16

Cecum and proximal loop of the ascending colon

Question 17

What does the lesser omentum cover?

Answer 17

The omasum (the omasum in cattle corresponds to the 8th - 11th ribs; lower in the cavity).

Question 18

What are the parts of the equine stomach? What is the capacity of the equine stomach?

Answer 18

From dorsal to ventral:
- Fundus (contains the blind sac dorsally and the non-glandular part of the stomach ventral to that)
- Margo plicatus (distinct line demarcating the non-glandular and glandular parts of the stomach)
- Body (contains the glandular part of the stomach)
- Pylorus

**The area where the esophagus enters the stomach is the cardia

Equine stomach has a capacity of about 3 gallons.

Question 19

What is the correct order of the equine intestinal tract from the cecum on?

Answer 19

1) Cecum
2) Right Ventral Colon
3) Sternal Flexure
4) Left Ventral Colon
5) Pelvic Flexure
6) Left Dorsal Colon
7) Diaphragmatic Flexure
8) Right Dorsal Colon
9) Transverse Colon
10) Descending Colon

Question 20

Which intestinal segment can move around quite a bit in the horse and why?

Answer 20

The jejunum can move around quite a bit; this is due to the large section of the mesojejunum (supporting structure)

Question 21

Where does the ileum open in the horse?

Answer 21

Directly into the cecum.

Question 22

Describe the course of the cecum in the horse. How big is the cecum?

Answer 22

1) The cecum is approximately 1 meter in length

2) It starts very high (dorsal) on the right body wall (within the paralumbar fossa); it then courses medially, cranially and ventrally; the apex of the cecum lies just caudal to the xyphoid process of the sternum.

Question 23

Where is a very common site of impaction in the horse?

Answer 23

The transverse colon.

Question 24

How many bands does each section of the cecum and colon have?

Answer 24

Remember the “phone number”: 444-1322

So…

Cecum = 4 bands
Right Ventral Colon = 4 bands
Left Ventral Colon = 4 bands
Left Dorsal Colon = 1 band
Right Dorsal Colon = 3 bands
Transverse Colon = 2 bands
Descending Colon = 2 bands