1. Digestive System

2. Digestive System
Large complex molecules broken down into simpler molecules
Long tube beginning with mouth and ending with the anus

3. Digestive Systems
Man & Pig have a simple stomach with an extensive intestinal system
Ruminants have a complex stomach with a simpler intestinal system
Horses & Rabbits have a simple stomach with an extensive intestinal system and an enlarged cecum

4. Digestive System Mouth: “Prehension” tool (grasps food)
Salivary Glands secrete juices containing enzymes (digest food)
Chewing food breaks down also
Esophagus: muscular tube that connects mouth to stomach
Peristaltic Movement: sequential contraction of ringlike muscles
Reverse Peristalsis = blowing chunks

5. Simple Stomach Muscular contractions break down food
Enzymes break down food:
Gastric: proteins
Liver & Pancreatic: fats

7. Ruminant Stomach
Stomach occupies 3/4 of abdominal cavity, mostly on the left side
Rumen (paunch): 80% of stomach, lighter food collects here
microbes digest cellulose
lots of water
Reticulum (hardware stomach): 5% of stomach, heavy foreign items are trapped here

8. Ruminant Stomach Omasum (many plies): 8% of stomach, absorbs water
Abomasum (true stomach): 8% of stomach, typical enzyme activity
Rumination: regurgitation, rechewing of food

10. Digestive System
Small Intestine: long coiled tube connecting stomach to large intestine
rest of the digestion and absorbtion takes place here
surface covered with villi (surface area)
Large Intestine: Cecum, colon, rectum
absorbs water (makes feces more solid)
some vitamins & minerals absorbed here
Cecal Fermenters (Horse): similar to rumen

11. Digestive System Accessory organs:
Pancreas secretes enzymes to break down fat
Liver (largest internal organ) secretes bile, which digests fats
also stores iron