nonruminant digestive systems –aves (birds)
TRANSCRIPT
Nonruminant Digestive Systems –Aves (Birds)
Bird Digestive System
1. beak tear food material into smaller particles.
2. travel down the esophagus to the crop.
The Process of Digestion
Bird Digestive System
The Process of Digestion
3. Birds will swallow small particles of gritty material (sand and small rock in the wild) and this grit collects in the crop.
Birds utilize this grit to “grind” particles of food into smaller pieces.
Water is also added to the food material in the crop.
Bird Digestive System
The Process of Digestion
Saliva mixes with the food in the mouth to begin breaking down simple carbohydrates into simple sugars.
Amylases (enzymes that breakdown starch into sugars) found in saliva break certain chemical bonds to begin the process of carbohydrate digestion.
Bird Digestive System
The Process of Digestion
4. Food then travels down the esophagus to the proventriculus, where it mixes with highly acidic gastric juices.
The proventriculus acts similar to the stomach of other animals.
Food material at this point has a mushy consistency.
Bird Digestive System
The Process of Digestion
5. Food material then moves to the gizzard, which is a very muscular organ
Food is physically ground into smaller pieces.
Bird Digestive System
The Process of Digestion
Food material that leaves the proventriculus is called chyme.
6. Chyme passes from the stomach to the first part of the small intestine, called the duodenum.
Bird Digestive System
The Process of Digestion
In the duodenum, the pancreas secretes enzymes that degrade sugars, fats, and proteins.
Bird Digestive System
The Process of Digestion
As chyme is moved through the duodenum, nutrients are absorbed into the bloodstream through small finger-like projections in the interior of the small intestine, called villi, as the nutrient-filled food mixture is squeezed by the peristalsis, making it more solid.
Bird Digestive System
The Process of Digestion
This process continues through the second part of the small intestine, called the jejunum.
Chyme is continually compressed as it passed through the third part of the small intestine, called the ileum.
Bird Digestive System
The Process of Digestion
7. Chyme then moves into the large intestine, where moisture is continually removed by peristalsis.
Bird Digestive System
The Process of Digestion
8. Food material is then collected in the cloaca, and then is removed through the vent.
Bird Digestive System