digestive physiology Flashcards
digestion
process of converting complex nutrients into forms that can be absorbed
prehension
grabbing the food with the mouth
mastication
mechanical digestion
types of digestion
chemical and or microbial digestion
absorption definition
process by which digested nutrients cross gastrointestinal membranes
carnivore diet
> 80-90% animal based diet
chemical digestion
very limited microbial digestion
omnivore diet
meats
highly digestible plant components
chemical digestion
microbial digestion is limited to very limited (species dependent)
herbivores
primarily eat forages (low digestible plant components)
microbial digestion is primary
chemical digestion is secondary
4 types of digestive tracts
monogastric
ruminent
non-ruminent herbivore
modified monogastric
mouth
saliva and mastication
esophagus
connects mouth to stomach
monogastric - one way
ruminants - both ways (rumination)
stomach
chemical digestion
mucous cells
secrete alkaline mucus that protects the epithelium against shear stress and acid
parietal cells
secrete hydrochloric acid
chief cells
secrete pepsinogen (proteolytic enzyme)
g cells
secretes gastrin
amylase
converts complex carbohydrates to glucose
protease
converts proteins to amino acids
lipase
converts complex lipids to fatty acids
reticulum
honey comb pattern (strainer)
rumen
has papillae - increased surface for VFA’s to be absorbed
omasum
water strainer (reabsorbing water)
abomasum
gastric stomach in ruminants
glucose can be digested by ..
chemical and microbial digestion
starch can be digested by …
microbial digestion
cellulose can be digested by …
microbial digestion
VFA’s
Acetic
propionic
butyric
groove responsible for rumen development
ruminoreticular groove
monogastric digestive tract
mouth –> mastication (mechanical) and saliva (chemical)
esophagus –> transport
stomach –> chemical digestion
small intestine –> proximal (digestion) and distal (absorption)
cecum –> blind pouch
large intestine –> h2O absorption
non-ruminent herbivore digestive tract
mouth –> mastication (mechanical) and saliva (chemical)
esophagus –> transport
stomach –> chemical digestion
small intestine –> proximal (digestion) and distal (absorption)
cecum –> microbial digestion
large intestine –> H20 absorption and microbial digestion
modified monogastric
esophagus –> transport
crop –> moistening
proventriculus –> chemical digestion
gizzard –> mastication
small intestine –> proximal (digestion) and distal (absorption)
ceca –> two lobes
large intestine –> H20 absorption
cloaca –> defecation
ruminants
mouth –> mastication (mechanical) and saliva (chemical)
esophagus –> transport (go both ways)
rumen (fermentation vat/VFA’s absorbed) -> reticulum (strainer) -> omasum (water absorption) -> abomasum (gastric stomach, digests microbes and VFA’s (from feed)
small intestine –> proximal (digestion) and distal (absorption)
cecum –> microbial digestion
large intestine –> H20 absorption and microbial digestion