A. Reticulum

1. A. Reticulum • Tough, honeycomb like structure, puncture resistant, lower portion of the • ‘Catches’ foreign objects and prevents them from causing further harm downstream of the rumen. • Once items “sink” and are “caught” they stay there forever unless removed

2. Reticulum – full – left Reticulum – enlarged – bottom left Reticulum – cleaned - lower

3. Telephone Cord

4. Wire

5. Sponge taken from digestive system of an animal

6. T. Left – Cow magnet used verses after harvest. B. Left – New magnet B. Right – Insertion Using balling gun

7. A. Omasum • Section that is round and muscular • Resembles pages of an open book • “Grinds” the food material and prepares the food material for chemical breakdown. Absorbs water, volatile fatty acids and nutrients • Folds trap digested particles to maximize absorption • Injects a soupy mixture of partially digested forage and microbes into this structure

8. A. Abomasum • It operates much like our own stomachs (but handles more bacteria than ours) • It secretes acid and digestive enzymes • Where the majority of chemical breakdown of food material occurs. • Mixes in digestive enzymes (pepsin, rennin, bile, etc.).

9. Let’s Review: With a partner, digest the snack in front of you and describe what is happening to the food as it moves through your GI.

10. 9. Small Intestine - where most of the food material is absorbed into the bloodstream • Contains three sections: • duodenum • jejunum • ileum

11. A. Duodenum: first section (active digestion) -Receives secretions from: Pancreas: acts on proteins, carbohydrates and lipids Liver: bile (stored in the gallbladder) breaks down fat. *Horses do not have gallbladders B.Jejunum: middle section; active in nutrientabsorption C. Ileum: last section; active in nutrientabsorption

12. Small Intestines • Walls of the S.I. are lined with a series of fingerlike projections called villi, which in turn have minute projections called microvillithat increase the nutrient absorption area.

13. 10. Large Intestines • Site of water restoration • Secretion of some mineral elements • Storage reservoir calcium • of undigested GIT contents. • Bacterial fermentation: • Synthesis of some water-soluble vitamins and vitamin K. • Some bacterial breakdown of fibrous ingredients. • Synthesis of some protein,

14. A. Cecum: • first section • size varies considerably in different species; • No significance in the pig or human (dead end) • IMPORTANT in horse and rabbit • Bacterial breakdown of cellulose and other carbohydrate material to produce VFAs thus, the horse can utilize fibrous feeds. • Site of bacterial synthesis of water-soluble vitamins and protein.

15. B. Colon: • middle section • largest part of the L.I. • Primary area of water restoration from intestinal contents. • C. Rectum: last section of the L.I. and the end of the digestive tract before the unabsorbed material (feces) is excreted out the anus (preparation for excretion) (poop chute)

16. 11. Anus - opening through which the waste is removed. Controlled by sphincter muscles, that also help protect the opening.

17. Let’s Review: Go to a review station and put terms of the digestive tract in order using only each other as resources (no notes – TALK it through!)