Set 3

Question 1

Why are the terms monogastric and polygastric inappropriate?

Answer 1

There are not true multiple stomaches there are just multiple compartments within the one stomach.

Question 2

What are the names of 2 and 3 compartment units of the ruminant stomach?

Answer 2

Forestomach is the first three chambers and the ruminoreticulum is the first two chambers.

Question 3

Describe the lining of each of the 4 compartments.

Answer 3

The first three chambers are lines with the non glandular with stratified squamous lining. Reticulum has honey comb cells. Rumen is lined by papillae. Omasum is lined by the parallel laminae. Abomasum is lined by the glandular walls rather than stratified squamous.

Question 4

Differentiate between ruminal grooves and pillars.

Answer 4

Grooves are external while pillars are internal.

Question 5

Which forestomach groove is internal?

Answer 5

The reticular groove is the internal groove.

Question 6

Why must a ruminant animal maintain an upright position continually?

Answer 6

Ruminants must maintain an upright position so that the gas produced in the rumen does not get trapped. Trapped gas will leads go a bloated gut and kill the animal after time. The cardia of the stomach must be above the level of the ingesta so gas can excape.

Question 7

What is meant by submersion of the cardia in ruminants?

Answer 7

Submersion of cardia is when the ruminant lies in its side. The animal is not able to release gas.

Question 8

What is another less critical reason for the upright position?

Answer 8

The other reason for an upright position is to leave the newly ate food on top of fluid so it can be sucked back up into the esophagus and chewed again.

Question 9

What is the structure that allows milk to bypass the rumen in calves? Why is this important?

Answer 9

The reticular groove closure allows bypass of the rumenoreticulum. Rumen meant for digestion of fibrous plants not milk.

Question 10

Penetration of a nail or wire through the cranial aspect of the reticulum could damage which organ?

Answer 10

Pericardium; heart

Question 11

What are 4 attachment points of the ruminant stomach?

Answer 11

Diaphragm at the cardia, dorsal adhesion of the dorsal sac to dorsal wall of abdominal cavity and the greater and lesser omentum

Question 12

Why is the liver and duodenum displaced in an LDA?

Answer 12

The liver and the duodenum are drug by the abomasums so they are displaced in LDL. The lesser omentum attaches to abomasums and liver.

Question 13

Differentiate between omental bursa and omental recess.

Answer 13

The bursa is the space between the deep and superficial omentums. The recess is where the intestines are contained because it acts as an omental sling.

Question 14

What part of the ruminant stomach lies in the omental bursa?

Answer 14

The ventral sac of rumen is the part of the rumen that lies within the omental bursa.

Question 15

The lesser omentum of the ox attaches to what specific part of the gut and to which side of what solid organ?

Answer 15

The lesser omentum extends from the abomasal lesser curvature to the liver and covers the visceral (ventral) surface of liver.

Question 16

What structure is covered by the lesser omentum in the ox?

Answer 16

The lesser omentums covers the omasum part of the stomach.

Question 17

What is the location, structure and apparent function of the omasum?

Answer 17

Location: lies to the right of the reticulum, ventral to the liver and dorsal to the initial part of the abomasum into which it drains. Structure and function :contains many parallel laminae that trap ingesta in between themselves and thereby squeeze water out of the fluid ingesta which enters from the reticulum.

Question 18

How might it be blocked?

Answer 18

The omasum can be blocked due to a cow eating their own placenta. The placenta is fresh material and is poorly digested in the ruminoreticulum and hence can plug up the omasal canal.

Question 19

Why is the small intestine much longer in ruminants than the horse?

Answer 19

The rumen must have a longer small intestine than a hind gut fermented like a horse because ruminants must digest the rumen bacteria that has been built from the products of rumen fermentation.

Question 20

Why is the spiral colon of ruminants easily discernable on a left view but not on a right view?

Answer 20

The spiral colon is covered by mesentery on the right view so it is not seen.

Question 21

How is the muscle coat and “geometry” of the layout of the spiral intestine of pigs different from that of ruminants?

Answer 21

The pigs spiral colon is three dimensional in shape and has larger centripetal coils on the outside and smaller centrifugal coils on the inside. They also have rudimentary bands and sacculations on the cecum and centripetal spiral colon. Pigs also have an ileal papilla that contains erectile tissue where the ileum enters the colon.

Question 22

How do the first two compartments of the camelid stomach differ from those of ruminants?

Answer 22

The first compartment is like the rumen in that it is the largest compartment. However, it is different from rumen as it lacks papillae and has glands in the wall. The second compartment is also lined by glandular saccules that are more complex than the saccules found within the first compartment. The second compartment has conical papillae which is similar to that of the omasum which had laminae in the rumen.

Question 23

Why is the lesser omentum so small in the horse?

Answer 23

The lesser omentums is smaller in the horse due to the reduced size of the lesser curvature.

Question 24

Relate bowel displacement to the main attachment points of the equine cecum/large colon.

Answer 24

The cecum is attached to the dorsal body wall ventral to the right kidney.

Question 25

Impaction occurs at what three sites where the equine gut narrows?

Answer 25

Cecal/colic orifice, pelvic flexure of colon, and right dorsal colon/ small colon junction

Question 26

In the horse what organ(s) is/are attached to the surface of each kidney?

Answer 26

The surface of the left kidney attaches to the nephrosplenic ligament and the right kidney attaches to the cecum and the pancreas.

Question 27

Where does equine bowel entrapment occur, how are these sites formed, and which bowel is affected?

Answer 27

The left colon entrapment occurs where the nephrosplenic ligament attaches to the left kidney. Also, the epiploic foramen entraps the loop of the small intestine.

Question 28

What forms the bands of the equine large intestine?

Answer 28

The bands are formed from condensations of the longitudinal smooth muscle that pull the wall into pleats or sacculations. Bands are always associated with sacculations.

Question 29

How many bands are found on the cecum, ventral colons, small colon?

Answer 29

The cecum and ventral colon both have four bands associated with them while the small colon only has two bands associated with it.

Question 30

Which species have intestinal bands?

Answer 30

Horses, pigs, humans and rabbits have intestinal bands.

Question 31

The epiploic foramen is the entrance to what?

Answer 31

The epiploic foramen is the entrance to the omental bursa.

Question 32

What vessels bound the foramen on the dorsal and ventral sides? (epiploic foramen)

Answer 32

The foramen lies between the portal vein (ventral) and the causal vena cava (dorsal) .

Question 33

To enter the foramen in the horse one must pass over what portion of gut and under which organ? (epiploic foramen)

Answer 33

The organ that must be passed over duodenum and under the liver.

Question 34

Trace the normal route of ingesta passage thru the equine intestines.

Answer 34

Duodenum, jejunum, ileum, cecum, right ventral colon, ventral diaphragmatic flexure, left ventral colon, pelvic flexure, left dorsal colon, dorsal diaphragmatic flexure, right dorsal colon, transverse colon, descending colon

Question 35

What is intussusception and where does it usually occur in the horse?

Answer 35

Intussusception is defined as one part of the gut going into the other part of the gut. In the horse this usually occurs in the ileum.

Question 36

Compare the locations of the descending duodenum and the descending colon. The duodenum loops around what structure in the horse?

Answer 36

The duodenum loops around the base of cecum in the horse.

Question 37

How does the equine descending colon differ from that of other species?

Answer 37

The colon is elongated in the equine so that ingesta can dry out before being defecated.

Question 38

Which animals or groups of animals lack a gallbladder?

Answer 38

Crevids or animals with antlers, camelids, horses, giraffe, and the rat all lack a gall bladder.

Question 39

What are the flexures that are the midpoints of the ascending colon of the ox, pig, and horse?

Answer 39

Midpoint of the ascending colon in the ox and pig is called the central flexure. In the horse it is called the pelvic flexure.

Question 40

Compare the attachments of the spleen of dog, ruminant, llama and horse.

Answer 40

Attachment of most domestic animals spleen is they are mobile and lies in the greater omentum. The attachment of the spleen in ruminant animals is that it is fused to the rumen.

Question 41

Which animal has the largest spleen (proportionally) and what are the advantages of such?

Answer 41

Horse has the largest spleen because they are very athletic.

Question 42

Which animal has an ileocecal orifice and why is this different from other domestic animals?

Answer 42

Horse has an ileocecal orifice and this is different from other species as the equine ileum enters the cecum it is entering derivate of the colon.

Question 43

Which animals lack cecocolic orifices?

Which animal has a vermiform (worm like) appendix?

Answer 43

Rabbit

Question 44

Compare foregut vs. hindgut fermenters. What are the advantages and disadvantages of each?

Answer 44

Advantages: can break down nutrients more quickly, quick excretion, less fermentation loss of soluble nutrients
Disadvantages: less room for storage, less time for fermentations, no nitrogen recycling, no regurgitation possible

Question 45

If you practice near Rochester, MN, your most wealthy equine clients will probably be physicians. What should you know about differences between human and veterinary gut nomenclature in order to explain a colic case to one of these clients? (refer back to dog notes)

Answer 45

Human: jejunum is cranial 40% and ileum is caudal 60%

Veterinary gut: ileum is short terminal segment of small intestines