Biology / Unit 12 Bio 2769 short lesson, about 20 seconds
Avian Digestive Adaptations
Captions available
The idea
Birds lack teeth, instead using a crop to store food and a two-chambered stomach — the proventriculus for gastric juices, the gizzard for grinding.
In practice
Some birds swallow grit that lodges in the gizzard to help grind food in place of teeth.
Where people slip
The gizzard grinds food mechanically with swallowed grit — it secretes no digestive enzymes itself; the proventriculus supplies those.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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