Digestive System

Digestive System Rap

Job of Digestive SystemBreak down food (macromolecules) into nutrients & energy

Review: MacromoleculesWhat macromolecules do we eat?Proteins: Meat, Nuts Lipids: Oils, FatsCarbohydrates: Breads, Sugars

Review: Food EnergyWhich macromolecule is our main energy source? Carbohydrates

Which macromolecule stores the most energy? LipidsReview: Food Energy (cont.)

The Food Pyramid

NutritionNutrients: Anything that promotes growth Vitamins (Vitamin C) Minerals (Iron) Macromolecules

Two Types of DigestionMechanical physically breaking food into smaller pieces (mouth)Chemical food molecules are broken down by acids and enzymes (stomach, small intestines)

Digestive System

Tracking a Piece of Food1. Mouth2. Esophagus3. Stomach4. Small Intestine5. Large Intestine6. Rectum 7. Anus

SwallowingPeristalsis: wavelike movement of muscles pushes food through digestive tract

My food went down the wrong pipe!2 tubes in throat: trachea & esophagusesophagus connects mouth to stomach How does food know which tube to go down?

epiglottis

3 Jobs of StomachStore food & liquidMix food & digestive juices (HCl)Empty into small intestine

Digestive JuicesAssist in breaking down of foodEx. EnzymesAcid Reflux

Small IntestineAbsorbs greatest amount of nutrientsCovered with tiny finger-like projections villi ~20 ft long!

Villi

Increase surface area for better absorption (like a towel)

Large IntestinePrepares waste for removal by absorbing water~5 ft long!

Digestion: Helper OrgansSalivary Glands: produce saliva starts breaking down carbohydratesPancreas: produces enzymes & regulates glucose levels

Liver:Produces bileFilters bloodDigestion: Helper Organs (cont.)

Gall Bladder: stores bileHelps digest fatty foodsDigestion: Helper Organs (cont.)