Digestion (Stomach and small intestine) Flashcards
what type of stomach do monogastrics have, and what is the name for this stomach in ruminants and in birds
glandular stomach, and it is the abomasum in ruminants and the proventriculus in birds
what is the region of the stomach that is closet to the heart, and what does it produce
cardiac region
-produces mucus that protects the lining from acid
what is the muscle called that is at the end of the esophagus and the entry way to the stomach
cardiac sphincter
what is the region of the stomach that is right after the cardiac sphincter
esophageal area
what is the middle region of the stomach called and what does it produce
fundic area (fundus) -digestive enzymes
what is the region of the stomach that is below the fundus and what does it produce
pylorus
-mucus production
what is the muscle called that is the exit point of the stomach
pyloric sphincter muscle
what are the contents of the stomach called
chyme
3 functions of stomach digestion
- temporary storage for consumed feed
- mixing action
- digestive enzymes from lining (gastric pits)
how does the stomach provide temporary storage for consumed feed
folds in the lining allow stretching to accomadate larger meals
what causes the mixing action in the stomach
peristaltic contractions
- mix contents and encourage feed exit
what are 3 enzymes secreted from the lining of the stomach
- pepsin
- rennin
- lipase
what cells produce both pepsin and rennin enzymes
chief cells
where are polypeptides and peptides absorbed
small intestine
how long does the coagulated milk caused by rennin stay in the stomach to improve digestive efficiency
8 to 12 hours
what does lipase break fats and oils into and how do fatty meals affect stomach contractions
breaks them down into free fatty acids and monoglycerides
- fatty meals slow stomach contractions for more efficient digestion
what digestion does NOT happen in the stomach
carb digestion
what are 5 things that slow stomach activity and can actually inhibit digestion
- fear
- anxiety
- depression
- pain
- stress
what activity can actually increase digestive efficiency
eating with friends
- laughing
- talking and thinking about food
what are 2 other secretions produced by parietal cells
- hydrochloric acid
2. mucus
function of HCL in the stomach
lowers pH of chyme to 2-3 to increase activity of stomach enzymes and to kill diseases
function mucus and where is it produced
lines entire stomach and protects lining from acid
- produced in goblet cells
How much absorption happens in the stomach and what is abosrbed
very little absorption
- absorbs H20, alcohol and some minerals
what is the interior of the small intestine called
lumen
what is the first 12 inches of the SI called
duodenum
what happens in the duodenum
many digestive secretions
what is the middle section of the SI called and what happens there
jejunum
-digestion and absorption of end products
what is the last section of the SI intestine called and what happens there
ileum
-mainly absorption
what causes the inner lining of the small intestine to increase by 1000x
folds of tissue and villi
2 causes of villi damage
internal parasites
viral bacterial infections
what are atrophied villi
villi that have a loss of absorptive surface area
what are the 3 layers of the small intestine from outermost to inner most
- tough connective tissue
- muscle layer
- mucosal cell layer
what can the tough connective tissue of the small intestine be used for when harvested from an animal
to make violin strings or sutures
what are 3 accessory digestive organs
- liver
- gallbladder
- pancreas
What does the liver produce and where does it send it to
- Produces bile
2. continuously sends to gallbladder for temporary storage
What occurs when the body senses that fats/oils have been consumed
- gallbladder contracts and sends bile to SI through bile duct
what does bile help do
digest fats/oils more efficiently
where does pancreatic juice enter the small intestine and through what duct
- secreted into duodenum after a meal through the bile duct
what are the 4 important contents of pancreatic juice
- sodium bicarbonate (pH 9-11)
- Protease enzymes
- Amylase
- lipase
what does sodium bicarbonate do in the small intestine
- neutralizes acidity of chyme
2. enzymes in SI work best at higher/neutral pH
what 2 protease enzymes are secreted from the pancreas
- what do they work on
- what are the end products
- trypsin
- chymotrypsin
- works on dietary proteins and polypeptides
- end products are small peptides
Raw soybeans
- what inhibitor does it contain
- who do you not feed raw soybeans to
- what can you do to destroy inhibitor
- what can the rumen microbes do to the inhibitor
- trypsin inhibitor
- avoid feeding to young monogastrics
- heat soybeans
- rumen microbes can deactivate inhibitor
what are 2 other factors that can decrease digestibility of diet proteins
- type of protein
- keratin protein is not digestible - heat damaged feeds
- heating higher than 140-160 degrees F
what is hydrolyzed feather meal
steam treated feathers under pressure
breaks peptide bonds which increases digestibility of protein
feed to hogs and poultry
where is the main site of starch digestion in monogastrics
small intestine
What does amylase break down and what does it break down into
- breaks down starch
2. breaks it into dextrins and maltose units
what 4 things can increase starch digestibility
- steam flaking
- decrease particle size (grind) - increases surface area
- high moisture (18-30% moisture)
- Genetic varieties
What does lipase from the pancreas break down and where do the end products go
- breaks fats/ oils into Free FA’s and monoglycerides
- end products go into lymph
-SI is main site of digestion of fats and oils in monogastrics
what do bile salts help digest more efficiently
- fats and oils
how do bile salts help digest fats and oils
- they are amphipathic and they prevent the fats and oils from clumping back together (emulsifiy)
- this causes in increase of surface area and lipase activity
what do nutrients have to do in the small intestine with regards to microvilli
nutrients has to touch microvilli
what are the 3 disaccharidases produced in the brush border
- sucrase
- lactase
- maltase
what disaccharidase do ruminants have very little of
surcrase
what happens if disaccharides are not digested in the SI in young animals
it goes to the large intestine and ferments which will cause gas build up
where do the end products from disaccharidases go after digestion
blood
when is lactase production and activity highest
right after birth
- increase in milk consumption
- lactase production decreases after weaning
what is another name for maltase
dextrinase
what 2 enzymes have low activity in newborns
amylase and maltase
what cant baby pigs digest very well from birth to 25 lbs
soybean meal and corn starch
what do baby pig pellets contain
- dried whey (includes lactose)
- dried blood plasma
- dried egg
where does the last stage of protein digestion take place
small intestine and it goes into the blood
what is another enzyme produced in the brush boarder
- peptidase
what organ do all nutrients go to when they go into the bloodstream after digestion
liver
what is the web like tissue attached to the abdominal wall called
mesentery
