MAMMALIAN DIGESTIVE PHYSIOLOGY Flashcards
Oral Cavity
teeth/ jaws
- incisors (cutting)
- canines (grasping/tearing)
- Premolars/molars (occluding surface)
- carnassial teeth (carnivores)
- ruminant dental pad
salivary glands (3)
- parotid glands: watery solution- starch digestion
- submandibular glands (mucus)
- sublingual glands (mucus)
- pharynx
esophagus
transfers ingesta from pharynx –> stomach
controlled regurgitation in some species
mucus secreting cells
stomach
stores, macerates, triturates food (breaks down)
- protein digestion initiated
- pepsinogen + HCl = pepsin (endopeptidases)
- most species have a relatively simple stomach
small intestine
a major site for carbohydrate/fat/digestion
a major site for absorption of digestive end products
a major site for absorption of vitamins/ minerals
Duodenum
receives pancreatic and hepatic secretions
- pancreas: digestive enzymes
- lipase, protease/peptidase, amylase, lactase, maltase, sucrase
- Liver: bile (stored in the gall bladder)
- brunner’s gland: secrete alkaline fluid and mucus (pH balance)
Jejunum
absorbs products of digestion
- fats: fatty acids, monoglycerides
- carbohydrates: monosaccharides
- protein: amino acids, dipeptides
- minerals and vitamins
Ileum
absorbs bile acids and cobalamin (b12)
Large intestine
a major site for water and electrolyte mineral absorption
a major site for microbial fermentation in omnivores and hindgut fermenting herbivores
Cecum
the junction between SI and LI
- site of microbial fermentation
- maybe absent, small, large haustrated
Colon
site of microbial fermentation
may be small, large, haustrated
rectum
fecal excretion of undigested/ unabsorbed nutrients
Cloaca
combined fecal and urinary excretion
Carnivorous Mammals
mono-gastric (simple stomach)
no cecum
protein/fat very efficiently digested
Omnivorous mammals
mono-gastric
cecum
colon/ cecum may be hasutrated
hind-gut microbial fermentation
