Lab P1: Digestion Flashcards
Describe the mouth in digestion. Differences?
Mainly for mechanical digestion.
In humans and pigs, saliva contains amylase. This is enzematic of starch digestion.
What does ruminate saliva lack?
Amylase!
Describe the order of digestive organs in a non-ruminant. (Monogastric)
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.
Describe the order of organs in a ruminant animal.
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.
what is the order of a ruminate stomach?
Rumen, reticulum, omasum, abosmasum.
Reverse alphabetical.
How does the rumen funcsion?
A huge vat of fermentation where bacteria and protozoa break down forages using cellulose.
How do you know you are looking at the reticulum?
The inner linning looks like a honey comb!
What is the job of the reticulum?
Enzematic digestion.
Contracts to send food back up.
How do you tell apart the omasum?
It has a lot of folds! Called piles.
What is the point of the omasum?
Mechanical digestion.
Describe the abomasume.
True stomach. Same as ours. Mechanical, chemical, enzymatic digestion. Includes HCI.
Explain the role of the liver in digestion.
Secretes bile. It digests lipids/fats.
What does the small intestine do? How?
Lots of enzymatic digestions.
Major site of Absorbtion! Very vascular, skinny, tube like. Uses villi to absorb.
In a mongastric, what is the role of a cecum?
In a ruminate animal, what is the role of a cecum?
Clean up crew! Most cellulose should be gone by the time the food gets to the cecum.
Cecum is a _______. Explain.
Blind pouch. It is in the junction of the small and large intestine. Enters and exits the same way.
Difference between the cecum of a herbavore monogastric and a carnivore monogastric?
Herbavores have a big cecum, small liver
Carnivores have big liver, small cecum.
GIve a run down of the avian digestive system.
Mouth, esophagus, crop, proventriculus, polyoric spinchrer, gizzard, small intestine, two ceca, large intestine, cloaca.
Purpose of crop?
Storage. A little bit of enzymatic digestion.
Purpose of proventriculus?
Similar to our stomachs. Ezymatic and chemical digestion.
What does the proventriculus look like?
Forms a long tube C shape around gizzard.
What is the gizzard also called?
Ventriculus.
Gizzard purpose?
mechanical digestion. Acts like a grist mill.
How might the small intestines on birds look different?
The diameter might look even wider than the large intestine.
On birds, what do the ceca looj like?
On either side of the junction between large intestine and small intestine. Make a plus sign.
Describe cloaca.
Common exit for urinary, waste, and reproduction.
Describe the teeth of a carnivore.
Typicically have canines, have sharp and pointed molars and incisors.
Describe the teeth of a herbivore.
Generally dont have canine teeth. Large, flat, molars and incisors.
Describe the teeth of omnivores.
Typically have canines, but less pronounced. Molars and incisors are somewhere between carnivores and herbivores.
What are some high energy feeds?
Cereal grains, mill by products, fruits, nuts, syrups, root.
What are some protein supplements
Animal, marine, avain, and plant sources.
Define roughages?
feeds that are low in digestibility because of their high fiber content.
Almost every ingredient that end in ____ is a protein supplement.
Meal
Urea is for ______ only.
Ruminants.
Fats, oils, and syrups (molasses) are very high in what?
Energy.
All grains are considered to be __________
High energy feeds.
Minerals and vitamin supplement are usually mixed with _____ or a carrier such as ______
Salt, Rice hulls.
What is a key to identifying hays?
The seed heads and sometimes the leaves.
Which of the hays (forages) has a long, cylindrical seed head?
Timothy hay.
What is the main difference in the appearance of limestone and dicalcium phosphate?
Dicalcium phosphate looks like crystals or little pebbles whereas limestone in more of a powder
Which mineral feedstuff is blue?
Copper sulfate
What is the main difference in the appearance of oats and barley?
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
What is the main difference in the appearance of dried skim milk and lysine?
Lysine looks more like crystals or little pebbles whereas dried skim milk is a powder
Most of the feedstuffs classified as High Energy are what part of the plants from which they come?
Seed or grain
What is the main difference in the teeth of monogastric herbivores compared with ruminants?
Ruminants do not have any front teeth (incisors) in their upper palate whereas monogastric herbivores
such as horses and rabbits do.
What is the main difference in the teeth of herbivores compared with omnivores and carnivores?
Molars, incisors and canines are much sharper in omnivores and carnivores than herbivores
What is the main difference in the teeth of omnivores and carnivores?
Degree of sharpness of all the teeth, but this can probably be seen best with the molars
What does the lining of the reticulum look like?
Honeycomb
What does the lining of the omasum look like?
Folds or piles
What are two ways that you can distinguish between the pyloric and cardiac regions of the monogastric
stomach?
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.
What is the best way to determine whether you are looking at a digestive tract from a ruminant or a
monogastic animal?
Size and number of compartments in the stomach – ruminant has four compartments and usually will be
larger than the stomach of the monogastric animal
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?
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.
List three ways that you can determine that you are looking at a digestive tract from a chicken (or other
avian species).
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.
List two ways that you can distinguish between the large and small intestines.
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.
Where is the gall bladder located in the digestive tracts?
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.
Where is the proventriculus located in the avian digestive tract?
After the esophagus and just before the gizzard.
Where is the gizzard located in the avian digestive tract?
After the proventriculus and before the small intestines
Where is the pyloric sphincter located and what does it do?
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.
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.
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.
