GI Tract

Question 1

What are the sections of the GI tract?

Answer 1

-headgut
-foregut
-midgut
-hindgut

Question 2

What section of the GI tract differs the most between species?

Answer 2

foregut

Question 3

Digestive system

Answer 3

the digestive tract and liver, pancreas, and gallbladder

Question 4

Digestive tract

Answer 4

the path/organs involved in digestion from mouth to anus

Question 5

Function of the GI tract

Answer 5

-protection from microbial infections
-transport ingested food
-solubilize nutrients
-absorb nutrients
-excrete undigested residue and metabolic waste

Question 6

Mechanical digestion

Answer 6

-chewing
-GI tract contractions
-gizzard in birds

Question 7

Chemical digestion

Answer 7

-in the stomach/proventriculus/abomasum
-HCl and bile salts (small intestine)

Question 8

Enzymatic hydrolsis

Answer 8

macromolecules are broken down into constituent parts

Question 9

Two basic types of digestion

Answer 9

-simple hydrolytic
-fermentative

Question 10

Microbial activity of rumen contents

Answer 10

-make the energy in cellulose available
-synthesize B vitamins
-utilize nonprotein nitrogen or poor-quality dietary protein

Question 11

Gas production by ruminal ingesta

Answer 11

-CO2
-methane

Question 12

Properties of saliva

Answer 12

-lubricant (contains mucin)
-pig and humans have amylase
-ruminants have buffering acids

Question 13

What are the major buffers in ruminant saliva?

Answer 13

-bicarbonate
-phosphate

Question 14

Secretions that aid in digestion

Answer 14

-enzymes
-saliva
-acids/bases (HCl and HC3)
-biliary secretions (bile salts and buffers)
-hormones (gastrin, secretin, CCK, somatestatin)

Question 15

What is saliva stimulated by?

Answer 15

-psychic reflex
-food in mouth
-in ruminants: stimulation of cardiac region of the stomach by tactile stimuli

Question 16

Gastrin function

Answer 16

stimulation of acid secretion by gastric glands

Question 17

Secretin function

Answer 17

stimulation of volume and bicarbonate outputs of pancreatic secretion and in some species bile

Question 18

CCK

Answer 18

contraction of gallbladder and pancreas; stimulates synthesis of pancreatic enzymes; enhances insulin release; inhibits gastric acid secretions

Question 19

Somatostatin

Answer 19

inhibits release of gastrin, secretin, and CCK and inhibits ion transport to intestines

Question 20

Enzyme secretions in the mouth

Answer 20

salivary amylase in pigs and humans

Question 21

Enzyme secretions in the stomach

Answer 21

-pepsinogen
-HCl

Question 22

Enzyme secretions in the pancreas

Answer 22

-pancreatic amylase
-trypsinogen
-chymotrypsinogen
-lipase

Question 23

Enzyme secretions in the liver

Answer 23

bile

Question 24

Enzyme secretions in the small intestine

Answer 24

lactase

Question 25

Primary enzyme of starch digestion

Answer 25

amylase

Question 26

Products of starch digestion

Answer 26

maltose and glucose

Question 27

Primary enzyme of maltose digestion

Answer 27

maltase

Question 28

Products of maltose digestion

Answer 28

glucose

Question 29

Primary enzymes of lactose digestion

Answer 29

lactase

Question 30

Products of lactase digestion

Answer 30

glucose and galactose

Question 31

Primary enzymes of sucrose digestion

Answer 31

sucrase

Question 32

Products of sucrose digestion

Answer 32

glucose and fructose

Question 33

Primary enzyme of lipid digestion

Answer 33

lipase

Question 34

Products of lipid digestion

Answer 34

-monoglycerides -glycerol -fatty acids

Question 35

Primary enzymes of protein digestion

Answer 35

-pepsin -trypsin -chymotrypsin -carboxypeptidase -aminopeptidase -dipeptidase

Question 36

Products of protein digestion

Answer 36

peptides and amino acids