Alimentary System

Alimentary System

1. Digestive Processes

   • 1. Ingestion 2. Digestion 3. Absorption 4. Metabolism 5. Excretion

2. Components

   • Extra-abdominal: oral cavity, pharynx, oesophagus
   • Abdominal: Stomach, SI, LI
   • Accessory glands: salivary glands, pancreas, GB, liver
     • Extrinsic (remote from AC) Vs. Intrinsic (within AC)

3. Oral cavity

   • Lips - prehension
   • Tongue - prehension, mastication, taste, grooming, speech, heat-loss
   • Teeth & gums - mastication
   • Cheeks - mastication & storage
   • Salivary glands - lubrication and initial digestion
   • Pharynx - deglutition

4. Structure

   • Epithelium Submucosa Circular muscle Longitudinal muscle Adventitia

5. Peritoneum

   • Visceral & Parietal
   • Folds = mesenteries (carry neurovascular supply) and ligaments
   • Intra & retro peritoneal organs

6. Stomach

   • Compound - ruminants
   • Simple
     • 4 regions: cardia, fundus, body, pylorus

7. Small Intestine

   • Duodenum - short mesentery, pancreatic and bile ducts open into it
   • Jejunum & Ileum - diff distinguish, long mesentery
   • Enzymatic digestion and absorption

8. Large intestine

   • • Caecum • Colon • Rectum • Anal sphincter
   • • Secretes mucus • Absorbs water

9. Liver

   • Largest organ in body
   • • storage and metabolism of proteins, lipids and carbohydrates • Produces bile to emulsify fats • stores iron & vitamins • Detoxification

10. Gallbladder

    • Stores and concentrates bile (bile acids & salts, cholesterol)
    • Not found in horse or rat

11. Pancreas

    • Has body & 2 lobes
    • Exocrine function – pancreatic juice
    • Endocrine function – insulin, glucagon