Download VERTEBRATE DIGESTIVE SYSTEM Functions:

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Theory of mind in animals wikipedia, lookup

Insect physiology wikipedia, lookup

Herbivore wikipedia, lookup

Human digestive system wikipedia, lookup

Transcript
VERTEBRATE DIGESTIVE SYSTEM
Functions:
- mechanical breakdown - big lumps of food to small
- chemical breakdown - digestion → monomers
- absorption of monomers
- compact waste → feces, extract water → eliminate
Common features:
- longitudinal tube through body
- regional specializations along length
- basic wall plan common to all vertebrate groups
Trends:
- simple → complex as diet harder to digest
- easily digested food: simple, short gut
(filter-feeders, carnivores)
- "tough" food: gut longer, more complex (herbivores)
FUNCTIONAL REGIONS OF ALIMENTARY TRACT
chemical breakdown
mechanical mixing →chyme
-transit
large intestine
water absorption
compaction of feces
elimination
of feces
Kardong f 13-29
small intestine
absorption of monomers
mechanical
breakdown
of food bolus
FISH DIGESTIVE SYSTEM
Trends:
no oral salivary glands - water lubricates food
no separate stomach in some species
intestine surface area for absorption increased:
-long tube, folded/coiled in coelom
-mucosa folded internally
-spiral valve
-villi
ALIMENTARY TRACTS: PRIMITIVE FISH, ELASMOBRANCH,
TELEOST
Kardong 13-29
AMPHIBIAN DIGESTIVE SYSTEM
Trends:
ciliated oral epithelium
esophagus short, wide, ciliated
stomach regions: fundus, pylorus
-glands short tubular
small intestine coiled
-large mucosal villi, no glands
large intestine → cloaca
AMPHIBIAN ALIMENTARY TRACT
Kardong 13-32
REPTILIAN DIGESTIVE SYSTEM
-regional structure similar to amphibian gut
Trends:
gizzard: enlarged pylorus
- grind food
cecae: pouches off intestine
-more time for digestion
REPTILE
ALIMENTARY
TRACTS
Kardong 13-32
SNAKE FEEDING ON WHOLE PREY - NO MECHANICAL
BREAKDOWN, ALL CHEMICAL
Kardong 13-20
SPECIALIZED ORAL GLANDS IN REPTILE:
SNAKE VENOM GLAND
Kardong 13-36
BIRD DIGESTIVE SYSTEM
Trends:
keratinized beak - no teeth in modern birds
keratinized tongue - aids mechanical breakdown
crop: expanded esophagus
food reservoir - regurgitation for young
herbivores/seed eaters:
gizzard - mechanical breakdown
using stones, grit to grind food
MAMMALIAN DIGESTIVE SYSTEM
Diet-related specializations:
length of gut related to digestion time
-carnivores - chemical digestion fast, gut short
-herbivores - chemical digestion slow, gut longer
keratinized esophagus - rodents, herbivores
fermentation - extra chambers for bacterial action
to break down plant cellulose
-foregut fermenters
-intestinal fermenters