The Digestive and Renal Systems
Lesson 4
- The digestive system take the food we eat, breaks it down, and turns it into materials your body needs to live, repair itself, and grow.
- The part of this system that food runs through is called the gastrointestinal tract
or GI. There is also another name for the
GI, who can tell me what it is?
Lets take a look at the journey your food takes through your body.
- Our body needs certain nutrients daily that we can only get from food.
- What are the 3 most important nutrients our body needs?
1. Carbohydrates
2. Proteins
3. Fats
Terrific Teeth
Who can point out the four types of teeth?
- Digestion starts the second food enters your mouth.
- The grinding of your food with your teeth is called mechanical digestion.
- Incisors are a type of tooth and they are used for biting
- Cuspids or canines are sharp and made for tearing food.
- Molars and premolars are flat and are used for grinding.
The Structure of Teeth
- The first layer of your teeth is called enamel, it is not alive but it is the hardest structure in your entire body!
- The dentin comes next and it is alive since it contains cells. Its job is to absorb shock to protect the tooth.
- The sensitive part of your teeth is the pulp, this is where nerves and blood vessels are found. If the nerves in your teeth die the rest of your tooth will die and it will need replacing.
- The crown is the part of your tooth not covered up by gum.
Watch out for bacteria! Dont forget to brush!
- After you chew your food into small pieces, your body needs to break down the remaining food into chemicals. You do this through chemical digestion.
- This process is started with the help of your saliva.
- Saliva comes from salivary ducts in your cheeks.
- Your spit not only helps break down food, it also helps protect your teeth, defend your mouth against infection, and makes your food taste better.