1. The Digestive System

2. Similarities and Differences in Organ Systems Compared to Humans?
Perch Dissection
Similarities and Differences in Organ Systems Compared to Humans?

3. Similarities Differences Gallbladder Liver Pancreas Spleen
Pyloric caeca
Liver
Swim Bladder
Pancreas
Spleen

4. Pyloric Caeca

5. Digestive System Animation

6. Digestive System Parts
Mouth
Esophagus
Stomach
Liver
Gallbladder
Pancreas
Small Intestine
Large Intestine
Rectum and Anus

7. Mouth Physical Digestion – chewing 32 teeth Tongue
12 molars, 8 premolars, 4 canines, 8 incisors
Tongue
Taste buds distinguish between type of food
Moves food around forming bolus
Chemical Digestion – salivary amylase

8. Teeth and Taste Buds

9. Esophagus

10. Esophagus Receives bolus from the pharynx
Moves bolus to stomach by peristalsis

11. Stomach

12. Stomach
Receives bolus from the esophagus through the lower esophageal sphincter
Mixes the food with gastric juices containing HCl
Mucus helps protect the stomach lining
Pepsin - a digestive enzyme, helps break down large protein molecules
Creates a mixture called Chyme which is moved through the pyloric sphincter to the small intestines

13. Liver

14. Liver
Releases bile which emulsifies fats and help absorb fatty acids, cholesterol and some vitamins
Stores carbohydrates and vitamins and detoxifies many harmful substances

15. GallBladder

16. Gallbladder Stores bile that is produced by the liver
Gallstones – crystallized substances from bile in the gallbladder
Can result in surgery to remove gallbladder

17. Pancreas

18. Pancreas Secretes digestive enzymes Neutralizes chyme
Secrete Hormones:
Insulin – lowers blood sugar levels
Glucagon – raises blood sugar levels

19. Small Intestine

20. Small Intestine 9 to 10 feet long
Composed of 3 parts : duodenum, jejunum and the illeum
Most important absorbing organ
Digestion is completed in the small intestine

21. Large Intestine

22. Large Intestine Also called the colon Comprised of 4 sections
Ascending, Transverse, Descending and Sigmoid
Little or no digestive function
Chyme becomes feces which is stored until elimination

23. Rectum and Anus

24. Rectum and Anus Rectum – temporary storage facility for feces
Internal and External sphincters allow feces to be passed by muscles pulling the anus over the feces