Digestive Systems (Part 2) Flashcards
Why are there variations in digestive systems?
differences in food composition
What do differences in food composition lead to?
differences in the number of stomach chambers
What are the different stomach chambers?
- monogastric
- digastric
- trigastric
- four-chambered
What animals have a monogastric stomach?
most mammals
What animals have digastric stomach?
birds
What animals have a trigastric stomach?
pseudo-ruminants
What animals have a four-chambered stomach?
ruminant herbivores
What are the different sections of the four-chambered stomach?
rumen, reticulum, omasum, abomasum
What happens in the rumen?
fermentation by microbial symbionts
What is rumination?
regurgitation, rechewing
What is the function of the reticulum?
filters heavy/dense feed or indigestible objects the animal has eaten
What is the function of the omasum?
absorb water and other substances
What is the function of the abomasum?
breakdown feed, similar to stomach
Can non-ruminant herbivores or hindgut fermenters do regurgitation?
no
What organ do non-ruminant herbivores or hindgut fermenters have?
very large cecum
What is the function of a large cecum?
fermentation
What is coprophagy?
eating of feces/dung to get microbes
What do SOME non-ruminant herbivores or hindgut fermenters do to get microbes for fermentation?
coprophagy
What is the order of the ruminant stomach?
rumen -> reticulum -> omasum -> abomasum
What animals are pseudoruminants?
camelids, hippos, sloths
What does a trigastric stomach look like?
reticulum, omasum, and abomasum (no rumen)
What kind of cecum do pseudorumiants have?
large
What kind of cecum do digastric have?
paired ceca (2 cecums)
What unique features do digastrics have?
proventriculus, ventriculus, and paired ceca
What is the function of the proventriculus?
stomach, where chemical digestion begins
What is the ventriculus also called?
gizzard
what is the function of the ventriculus?
mastication (mechanical digestion)
