random
Digestive physiology is closely linked to what two things
feed selection (dietary strategies)
animals ability to derive nutritional benefits from particular types of feeds
what happens in the oral cavity
mechanical breakdown and mixing of food and saliva
goal: decrease particle size
what does storage impact?
extent of digestion
functions; major site for...
-digestion, absorbtion, secretion, immune function
why do we have a large intestine?
fermentation, produce feces, absorb nutrients
Why does the horse need to graze continuosly compared to the cow
Saliva is important for...
salvary enzymes
lubrication and oral health
amylase - digest starch, inactivated by low stomach pH
lingual lipase - hydrolysis triglycerides
two types of digestion?
enzymatic (gastric lipase, pepsin)
Duodeum
pH 5-6
less than 1 m long
enzymes from pancreas and Gall bladder
exocrine
frothy vs. free gas bloat
frothy has trapped gas bubbles, cant eructate
free-gas has something lodged in esophagus
what is the happens to the stomach in the cow when they are still nursing
stomach functions
storage, mixing, digestion, secretion, absorbtion
what is secreted and why?
acid(digestion)
buffer and mucus(fights against acid)
enzymes (catalyze reactions)
the pH becomes more neutral, less absorbtion of CHO, AA, di/tripeptides...absorbtion structures decrease
papillae are affected by
VFA (more = bigger papillae)
butyrate (more =bigger papillae)
rumination steps
1. regurgitate, 2. fluids swallowed, solids left, 3. remastication which disrupts fiber, 4. reinsalivation which decreaces foam which decreases bloat, 5. redeglutination
the slower the rate; the greater digestion
lower Kp by eating lipids, pyloric sphincter....
what does the stomach absorb?
water, alcohol, copper, floride, Mo, and asprin
peptides, CHO, and lipids are hydrolysed into
peptide then AA
monosachardes
monoglycerids and VFA's
what changes pH?
more acid, BE= lower pH
buffer = higher pH
Fermentation and respiration reaction
...
endocrine function
Isolets of langerhans
glucose homeostasis
4% pancreatic mass
alpha produce glycogen which raises blood sugar
beta produces insulin which decreases blood sugar
three types of glands and what they are used for
cardiac - produce mucus and buffer to protect the stomach
Oxyntic/peptic - acid production and enzyme production
pyloric - acid production and enzyme production
is the small i allo- or auto-?
auto-
more than 90% of undifferenciated cells become what?
how old is the oldest enterocyte and where would it be?
enterocytes
live for about 8 days
oldest on top
youngest on bottom of villi