Digestion

1
Digestion

• Intracellular
• endocytosis
• Extracellular
• Secretion
• Motility
• Digestion
• Absorption

2
(No Transcript)
3
(No Transcript)
4
Gut Dynamics
Influence of Diet on Digestive Tract Structure
and Function Intermittent Feeders
Reptiles- Burmese python
Hibernators- Marmot, Ground Squirrel
Migratory Birds- eg. Red Knots
5
Secor 2008
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
Herbivory
Advantages Abundant, easy to catch Disadvantag
es Low food quality, low digestability
cellulose, lignin, hemicellulose, xylan Plant
secondary compounds
10
Animals lack cellulase except ? Shipworms,
silverfish, firebrats bacterial and protozoan
symbionts Vertebrates Foregut
fermenters fundus kangaroo, sloth,
monkeys ruminants suborder Ruminantia Hindgu
t fermenters cecum rabbits,
horses caprophagy- rabbits, rodents Termites xy
lophagy obligate anaerobic flagellates
(acetogenic) Nitrogen Fixing Bacteria
11
Herbivorous land Crabs Christmas Island Linton
et al., 2004, 2006
12
Termites xylophagy Obligate anaerobic
flagellates (acetogenic) Nitrogen Fixing
Bacteria 1014g methane, 1016g CO2 / year (5-40
of global production)
13
(No Transcript)
14
(No Transcript)
15
Fun Facts

• Rumen up to 200lbs (25 gallons)
• Saliva 150 L/day
• Energy 70 from VFAs
• Methanogenesis 5 Kg Hay ? 191 L CH4
• Methane and Carbon Dioxide emitted by eructation
• Urea recycled to rumen to support microbes