1. Digestive System
Parts and Functions

2. Human Health and Digestion
Food is our primary source of fuel and building blocks for body growth, maintenance and energy requirements
Food can be contaminated with bacteria and also with chemical pesticides etc. This contamination can lead to health problems if ingested.

3. How much do you know?

4. Types of Digestion Physical
Biting and chewing to initially break down food for swallowing
Wetting to ease swallowing and movement
Peristalsis (rhythmic contractions) of smooth muscle around esophagus, stomach, intestines to move food through the alimentary canal (tube)
Churning of smooth muscle in stomach to mix food with digestive acid and enzymes

5. Chemical
Breaking down macronutrients into their smaller sub-units for absorption and transport around the body
PROTEINS amino acids
LIPIDS fatty acids, glycerol
CARBOHYDRATES simple sugars

6. Parts and Functions Mouth Esophagus Teeth Tongue Salivary glands
Epiglottis
Esophagus

7. Parts and Functions con’t
Stomach
Cardiac sphincter
Stomach Lining
(Acid secretion)
(Enzyme secretion)
(Mucus secretion)
Pyloric sphincter

8. Parts and Functions con’t
Small Intestines
Duodenum
(Enzyme secretion)
Ileum
Jejunum
Pancreas
Liver
Gall Bladder
(Neutralization of acid and emulsification of fats)

9. Parts and Functions con’t
Large Intestines
Ascending
Transverse
Descending
Rectum
(Storageand compaction)
Anus
(removal)

10. Enzyme Action
Enzymes are specialized proteins manufactured in the body to help chemical reactions take place
Some enzymes are especially designed to BREAK down macronutrients into their components!
PROTEINS amino acids
LIPIDS fatty acids, glycerol
CARBOHYDRATES simple sugars

11. Enzyme names end in “ase”
There are many digestive enzymes in the body and each has a SPECIFIC function
Enzymes act as “hands” that hold a molecule and allow a specific reaction to take place
Having healthy functional proteins means that this system works efficiently!

12. MOUTH Physical Digestion: Chemical Digestion: Biting, chewing
Wetting of food
SALIVA from salivary gland
Chemical Digestion:
Starts in the mouth
Especially for those components that are difficult to digest
AMYLASE
Enzyme found in saliva from salivary gland
Breaks down starch into simple sugars

13. STOMACH Physical Digestion Chemical Digestion
Peristalsis (from esophagus)
Churning (to mix)
Chemical Digestion
enzymes
HCl
Acid which helps to break down protein

14. INTESTINES: chemical digestion
Enzymes:
breaks down proteins and complex sugars into simple sugar components

15. Other Organs: chemical digestion
From Pancreas: pancreatic juice
Breaks down proteins into polypeptides and amino acids
Sodium bicarbonate: neutralize stomach acid
From Liver: bile salts
Manufactured in Liver, stored in Gall Bladder
mixes fats with water to assist in digestion