1. Digestion: Break-down of large, insoluble food molecules into small, water-soluble molecules using mechanical and chemical processes.
This occurs in the Alimentary Canal…

2. Alimentary canal – long muscular tube that runs from the mouth to the anus.
Peristalsis – muscular movement of food

3. Food group
Mechanical
-Teeth / stomach…
Specific enzymes do their bit…
End product & absorbed where…

4. Main regions of the alimentary canal and associated organs
Mechanical Digestion?
Chemical
Digestion?

5. Ingestion Teeth and jaws grind the food into smaller bits
Is the taking in of food into the mouth and swallowing it
Teeth and jaws grind the food into smaller bits
The saliva in the mouth contains enzyme (Amylase) which helps break up food chemically.
The oesophagus is the tube which connects the mouth to the stomach

6. Teeth and digestion There are four different types of human teeth:
1. Incisors for cutting.
2. Canines for piercing.
3. Pre-molars for cutting and crushing.
4. Molars for crushing and grinding.

7. Adults have a total of 32 teeth: 8 incisors, 4 canines, 8 premolars and 12 molars. You will have the majority of your adult teeth by the age of 14.

9. Year 9! Carnivores eg Cats, dogs and tigers …
The teeth in an animal skull can tell you lots about it. The type, shape and number of teeth can tell you about the animal’s diet.
Carnivores eg Cats, dogs and tigers …
Their diet consists mainly of meat.
• Carnivores have long, sharp teeth which indicate that the animal is a predator. These sharp pointed teeth are called canines.
• Canines are used to grab, hold and kill prey.
Canines also help to tear and rip flesh.
• Carnivores often have very small incisors and their molars are often more pointed, which they use to cut meat and bones.
Year 9!

12. State the causes of dental decay and describe the proper care of teeth.
Tooth decay is caused by a combination of bacteria and food.
A sticky substance called plaque which contains bacteria is constantly being formed in your teeth.
When bacteria feed on the sugars you eat, it forms acids.
Over a prolonged period of time, the acids starting destroying the tooth enamel, hence causing tooth decay.
Treatment / ‘Proper’ care by:
Brush teeth frequently.
Get fillings
Schedule regular dentist appointments
Eat less sugary foods.

13. Digestion Is the breaking-up of food into small soluble pieces.
Food in the stomach is mixed up and stored (turned into a soup-like liquid)
Stomach cells make enzymes (Pepsin) and hydrochloric acid are released to aid digestion
This acid also kills bacteria present in food.
Stomach – bag with lots of muscle in its walls…
Food held ~ 1-4 hours, liquids ~ a few minutes