Lab P1: Digestion

Question 1

Describe the mouth in digestion. Differences?

Answer 1

Mainly for mechanical digestion.

In humans and pigs, saliva contains amylase. This is enzematic of starch digestion.

Question 2

What does ruminate saliva lack?

Answer 2

Amylase!

Question 3

Describe the order of digestive organs in a non-ruminant. (Monogastric)

Answer 3

Mouth, esophagus, stomach, pyloric sphincter, small intestines, cecum, large intestines, anal sphincter, rectum.

The gall bladder and pancrease and Liver feed into the food after the small intestine.

Question 4

Describe the order of organs in a ruminant animal.

Answer 4

Mouth, esophagus, rumen, reticulum, omasum, abomasum, pyloric sphincter, small intestines, cecum, large intestines, anal sphincter, rectum.

The gall bladder, Liver, and pancreas all contribute to digestion after the small intestine.

Question 5

what is the order of a ruminate stomach?

Answer 5

Rumen, reticulum, omasum, abosmasum.

Reverse alphabetical.

Question 6

How does the rumen funcsion?

Answer 6

A huge vat of fermentation where bacteria and protozoa break down forages using cellulose.

Question 7

How do you know you are looking at the reticulum?

Answer 7

The inner linning looks like a honey comb!

Question 8

What is the job of the reticulum?

Answer 8

Enzematic digestion.

Contracts to send food back up.

Question 9

How do you tell apart the omasum?

Answer 9

It has a lot of folds! Called piles.

Question 10

What is the point of the omasum?

Answer 10

Mechanical digestion.

Question 11

Describe the abomasume.

Answer 11

True stomach. Same as ours. Mechanical, chemical, enzymatic digestion. Includes HCI.

Question 12

Explain the role of the liver in digestion.

Answer 12

Secretes bile. It digests lipids/fats.

Question 13

What does the small intestine do? How?

Answer 13

Lots of enzymatic digestions.

Major site of Absorbtion! Very vascular, skinny, tube like. Uses villi to absorb.

Question 14

In a mongastric, what is the role of a cecum?

Question 15

In a ruminate animal, what is the role of a cecum?

Answer 15

Clean up crew! Most cellulose should be gone by the time the food gets to the cecum.

Question 16

Cecum is a _______. Explain.

Answer 16

Blind pouch. It is in the junction of the small and large intestine. Enters and exits the same way.

Question 17

Difference between the cecum of a herbavore monogastric and a carnivore monogastric?

Answer 17

Herbavores have a big cecum, small liver

Carnivores have big liver, small cecum.

Question 18

GIve a run down of the avian digestive system.

Answer 18

Mouth, esophagus, crop, proventriculus, polyoric spinchrer, gizzard, small intestine, two ceca, large intestine, cloaca.

Question 19

Purpose of crop?

Answer 19

Storage. A little bit of enzymatic digestion.

Question 20

Purpose of proventriculus?

Answer 20

Similar to our stomachs. Ezymatic and chemical digestion.

Question 21

What does the proventriculus look like?

Answer 21

Forms a long tube C shape around gizzard.

Question 22

What is the gizzard also called?

Answer 22

Ventriculus.

Question 23

Gizzard purpose?

Answer 23

mechanical digestion. Acts like a grist mill.

Question 24

How might the small intestines on birds look different?

Answer 24

The diameter might look even wider than the large intestine.

Question 25

On birds, what do the ceca looj like?

Answer 25

On either side of the junction between large intestine and small intestine. Make a plus sign.

Question 26

Describe cloaca.

Answer 26

Common exit for urinary, waste, and reproduction.

Question 27

Describe the teeth of a carnivore.

Answer 27

Typicically have canines, have sharp and pointed molars and incisors.

Question 28

Describe the teeth of a herbivore.

Answer 28

Generally dont have canine teeth. Large, flat, molars and incisors.

Question 29

Describe the teeth of omnivores.

Answer 29

Typically have canines, but less pronounced. Molars and incisors are somewhere between carnivores and herbivores.

Question 30

What are some high energy feeds?

Answer 30

Cereal grains, mill by products, fruits, nuts, syrups, root.

Question 31

What are some protein supplements

Answer 31

Animal, marine, avain, and plant sources.

Question 32

Define roughages?

Answer 32

feeds that are low in digestibility because of their high fiber content.

Question 33

Almost every ingredient that end in ____ is a protein supplement.

Answer 33

Meal

Question 34

Urea is for ______ only.

Answer 34

Ruminants.

Question 35

Fats, oils, and syrups (molasses) are very high in what?

Answer 35

Energy.

Question 36

All grains are considered to be __________

Answer 36

High energy feeds.

Question 37

Minerals and vitamin supplement are usually mixed with _____ or a carrier such as ______

Answer 37

Salt, Rice hulls.

Question 38

What is a key to identifying hays?

Answer 38

The seed heads and sometimes the leaves.

Question 39

Which of the hays (forages) has a long, cylindrical seed head?

Answer 39

Timothy hay.

Question 40

What is the main difference in the appearance of limestone and dicalcium phosphate?

Answer 40

Dicalcium phosphate looks like crystals or little pebbles whereas limestone in more of a powder

Question 41

Which mineral feedstuff is blue?

Answer 41

Copper sulfate

Question 42

What is the main difference in the appearance of oats and barley?

Answer 42

Both are long seeds. The husk around oats usually is removed so it tends to be more cylindrical or
round, whereas the husk around barley is more angular – like a long diamond

Question 43

What is the main difference in the appearance of dried skim milk and lysine?

Answer 43

Lysine looks more like crystals or little pebbles whereas dried skim milk is a powder

Question 44

Most of the feedstuffs classified as High Energy are what part of the plants from which they come?

Answer 44

Seed or grain

Question 45

What is the main difference in the teeth of monogastric herbivores compared with ruminants?

Answer 45

Ruminants do not have any front teeth (incisors) in their upper palate whereas monogastric herbivores
such as horses and rabbits do.

Question 46

What is the main difference in the teeth of herbivores compared with omnivores and carnivores?

Answer 46

Molars, incisors and canines are much sharper in omnivores and carnivores than herbivores

Question 47

What is the main difference in the teeth of omnivores and carnivores?

Answer 47

Degree of sharpness of all the teeth, but this can probably be seen best with the molars

Question 48

What does the lining of the reticulum look like?

Answer 48

Honeycomb

Question 49

What does the lining of the omasum look like?

Answer 49

Folds or piles

Question 50

What are two ways that you can distinguish between the pyloric and cardiac regions of the monogastric
stomach?

Answer 50

Anatomical location – the cardiac region is above (cranial) to the junction with the esophagus and the
pyloric region is below (caudal) to the junction of the esophagus.

Muscle layer – the cardiac has a thin lining (epithelium) surrounded by connective tissue and a thin
muscle layer. The pyloric has a thin lining (epithelium) surrounded by a thick muscular layer.

Question 51

What is the best way to determine whether you are looking at a digestive tract from a ruminant or a
monogastic animal?

Answer 51

Size and number of compartments in the stomach – ruminant has four compartments and usually will be
larger than the stomach of the monogastric animal

Question 52

What is the best way to determine whether you are looking at a digestive tract from a monogastic animal
that is a carnivore compared with one that is either a herbivore or omnivore?

Answer 52

In monogastrics, the cecum is the main site of digestion of forages. Herbivores and omnivores would eat
more forages than carnivores. Consequently, the cecum should be the largest in herbivores; intermediate
in omnivores; and smallest in carnivores, relatively speaking. You have to consider the size of the rest of
the digestive tract when looking at the cecum. In other words, how large it is relative to the stomach.

Question 53

List three ways that you can determine that you are looking at a digestive tract from a chicken (or other
avian species).

Answer 53

Chickens (avians) have a gizzard, two ceca, crop, and cloaca (common exit) whereas digestive tracts from
other animals that we looked at in laboratory (mammals) do not.

Question 54

List two ways that you can distinguish between the large and small intestines.

Answer 54

Anatomical location and appearance – the small intestine will begin at the stomach, abomasum or gizzard
and end at the cecum (ceca). The large intestine begins at the cecum (ceca) and ends at the rectum. The
large intestine is larger in diameter than the small intestines with the exception being the avian digestive
tract in which they often are the same size or the small intestine is slightly larger.

Question 55

Where is the gall bladder located in the digestive tracts?

Answer 55

On the ventral surface of the liver. In some animals it is located in between two of the lobes and in others
it is located in a small indentation.

Question 56

Where is the proventriculus located in the avian digestive tract?

Answer 56

After the esophagus and just before the gizzard.

Question 57

Where is the gizzard located in the avian digestive tract?

Answer 57

After the proventriculus and before the small intestines

Question 58

Where is the pyloric sphincter located and what does it do?

Answer 58

The pyloric sphincter is a circular muscle between the stomach (abomasum) and the small intestine. It
serves as a gateway and opens and closes to allow food from the stomach to enter the small intestine.

Question 59

You are asked to perform necropsies on the digestive system of two animals. You are only given the portion of
their digestive tract from the esophagus to the rectum. Your supervisor tells you that both animals consumed
large amounts of roughages, but in addition to the roughages, only one also consumed quite a bit of fat and the
other ate almost no fat. Explain to me which organs and their corresponding appearances that you would look at
in each case to verify this information.

Answer 59

The key to this question is to think about organs in the digestive tract that is mainly involved in fat digestion.
The idea is that if a large amount of fat has to be digested, then the organ responsible or involved in its
digestion would have to be active and perhaps bigger. The gall bladder stores bile which is necessary for
emulsification of fat so enzymes can work on it better. Consequently, the animal eating the most fat should have
the larger gall bladder.

If your supervisor told you that the animal consumed large amounts of forage and it is a monogastric then the
cecum should also be large since this is where the microbes with the cellulase enzyme are housed. The concept
is the same in that if there is lots of roughage or fiber consumed, then the organ that is responsible for digesting
it would be larger. In monogastric, the cecum’s main role is the enzymatic digestion of roughage.