&Nutrition Digestive System DO NOW: What do you think is a healthy meal? Plan a healthy meal.

My Plate

Nutrients Food is too big to be absorbed into your cells Food must be broken down into its small parts . These small parts are called nutrients.

The 6 Basic Nutrients Nutrient Food Source Protein: Meat, fish, eggs, beans Needed for Growth and repair of tissue make enzymes and hormones

Carbohydrate Bread, cereal, pasta, fruit Nutrient Food Source Carbohydrate Bread, cereal, pasta, fruit (Whole grain metabolized better by your body) Needed for Energy Breaks down into sugar

Nutrient Food Source Fats Butter, oil, cheese, bacon Needed For: Second source of energy when carbs are used up.

Nutrient Food Source Vitamins Milk A&D, vegetables B A,B,C,D,E,K fruits C carrots A nuts E Needed for regulate growth, prevent disease, biochemical reactions

Nutrient Food Source Minerals Calcium - milk Iodine - added to salt Iron - green vegetables Iodine - added to salt Needed For: Strong bones and teeth Blood and other tissues

Nutrient Food Source Water All Foods , especially fruits and vegetables. Needed For: Dissolving substances, Blood, chemical reactions

DO NOW: Potato Chips are high in which 2 things? Carbs? Fat? Protein?

Fatty Foods High Protein Foods High Carbohydrate Foods

Functions of the Digestive System 1. Ingest: Food enters the body. Food contains nutrients needed for metabolism (chemical reactions). 2. Digest: Breaking down the food so cells can absorb the nutrients. 3. Absorption: Getting the nutrients to the cells. 4. Egest: Removing solid waste from the body.

1000 calories will be stored in fat. Why Eat? Food is needed to make Energy for life. This amount of energy is measured in calories. Unused calories of energy are stored in our fat cells for later. Eat 2000 calories of food. Use 1000 calories of energy. 1000 calories will be stored in fat.

Calorie (food energy) The amount of energy needed to raise the temperature of 1 kg of water 1 degree celsius.

Daily Caloric Requirements Male, aged 11-14 - 2800 Female, aged 11-14 - 2400 Male, aged 15-18 - 3000 Female aged 15-18 - 2100 1940 calories per day for women and 2550 for men Why do boys age 15-18 require more calories?

Exercise: Calories per hour Running: 700 Bicycling: 370 Skating: 450 Jogging: 600 1. How many hours would you have to run to burn up 1,400 calories? 2 . Which exercise burns the most calories? 3. You just ate 450 calories of candy, which exercise could you do for 1 hour to burn the same amount of calories?

DO NOW What are the 6 nutrients? What constitutes a balanced diet?

Why Digest? Carbohydrates, proteins and fats are too big to be absorbed into our bloodstream. Foods have to be broken down by enzymes before they are small enough to be absorbed.

Give an example of mechanical digestion. DO NOW: Give an example of mechanical digestion. Chewing

Pathway of Digestion mouth esophagus liver gallbladder stomach pancreas Small intestine Large intestine rectum anus

Mouth Mechanical and Chemical Digestion Mechanical = Teeth chew! Chemical = Enzymes in saliva digests starch into sugar!

Mechanical Vs. Chemical Digestion Is mechanical digestion a physical or chemical change? Mechanical is a physical change: breaking large pieces into smaller pieces. Is chemical digestion a physical or a chemical change? Chemical is a chemical change: chemically breaks large molecules into different, smaller molecules.

Enzymes Enzymes are special proteins that our body makes in order to digest food. Food might break down on its own in a million years, but enzymes speed this up. Enzymes speed up chemical reactions.

Enzymes will work more quickly on smaller pieces of food. WHY?

Increased Surface Area Chewing makes smaller pieces so that the enzymes will have more surface area to work on.

Which meat will be digested faster? Enzymes

Saltines Experiment

DO NOW: What are enzymes? What do they do? Where are they found?

Esophagus No Digestion here. Peristalsis: Waves of contraction of smooth muscle squeeze food down.

Stomach Blends food into liquid called Chyme Makes pepsin, Acid, and mucus Pepsin digests protein

Mechanical vs Chemical Mechanical digestion: Food is cut into smaller pieces. Chemical digestion: Enzymes break food molecules into their building blocks.

Small Intestine Absorption of Nutrients occurs ONLY here. Most digestion occurs here. Absorption of Nutrients occurs ONLY here.

Tapeworms live in small intestines The small intestine is the only place in the body where nutrients are absorbed. Tapeworms live there and absorb your nutrients before you can.

Nutrients have to be ________enough to be absorbed by the small intestine. How much surface area does the small intestine have inside?

Which one has more internal surface area?

How can the small intestine have so much surface area? Inside the small intestine are tiny wrinkles called VILLI.

Which road has more surface area?

Why is this good for the small intestine? There are more surfaces to absorb the nutrients!

If a stadium wants to sell their hot dogs FAST, how should they design the hot dog counter?

DO NOW List the pathway of food through the digestive system. Mouth Esophagus Stomach Small intestine Large intestine

6. Large Intestine Your food finally reaches the large intestine, and it is wet! All that is left is roughage / fiber that can’t be digested by humans. Water is reabsorbed. Bacteria live here and make vitamins for us.

Large Intestine How do feces move through the intestines? Peristalsis!

Problems in the Large Intestine Diarrhea: too wet. Constipation: not enough fiber. Colon cancer

Colon Cancer

DO NOW: 1. Which organ absorbs nutrients, fats, proteins, and carbohydrates? Small Intestine 2. Which organ absorbs water? Large Intestine

Accessory Organs Liver: Makes bile Gall Bladder: Stores Bile. Bile: Breaks down fat

PANCREAS Pancreas: releases digestive enzymes into the small intestine. This completes digestion. Bicarbonate is also secreted which neutralizes the acid from the stomach.

Liver, Gall Bladder, Pancreas

Can you identify all of these organs?

How many Digestive Organs can you label?