All living things maintain Homeostasis. Digestive System All living things maintain Homeostasis.

Objectives for the Week of 11/9 Identify and describe the function of the major organs of the digestive system Construct a model to illustrate the path of digestion Differentiate between mechanical and chemical breakdown Explain the difference between breakdown and absorption of nutrients

Digestion is…. Breaking nutrients into smaller pieces to make it easier for the body to absorb Cells will use nutrients to perform functions Importance: Allows organism to obtain vital nutrients for health and survival

Digestion Chemical digestion – the use of chemicals to break bonds *Enzymes: chemicals that speed up reactions * Acid: break down/dissolve Mechanical digestion – the use of physical force to break food into small pieces and increase surface area Ripping, Cutting, Tearing, Churning, Peristalsis Absorption – nutrients entering the cells of the body for use Absorption Chemical Digestion Mechanical Digestion

Nutrition Water Vitamins Minerals Biomolecules Carbohydrates Lipids/Fats Proteins

Mouth Type of digestion: Mechanical: Teeth – break food into pieces to increase surface area Chemical: Amylase= carb/starch enzyme in saliva Special information: Food forms a ball called a “bolus”

Esophagus- “food tube” Type of digestion: Mechanical: peristalsis = wave of contraction to move food Chemical: NONE Special information: muscular tube transports food to stomach

Stomach Type of digestion: Mechanical: Churning Chemical: Pepsin – enzyme for protein HCl Acid – weakens chemical bonds *Mucus- protects lining Special Information: Food forms a liquid called “chyme”

Small Intestine: 21 feet long Type of Digestion: Mechanical: peristalsis Chemical: from Pancreas, Gallbladder and Liver Bile [fats], Lipase [fats], Amylase [carbs] Protease [proteins] Special Information: Absorption: nutrients enter the cells by the bloodstream

Large Intestine: 5 feet long Type of digestion: Mechanical: Peristalsis Chemical: none Special Information: Absorption- water

Accessory Organs & Glands [food does NOT pass through] Salivary glands Liver Gallbladder Pancreas

Salivary Glands Function: produce saliva to lubricate and begin breaking down food Chemical: AMYLASE-Enzyme that breaks down starch

Liver- largest internal organ Functions: Storage Carbohydrates Detoxification Removes harmful substances Alcohol, medications Chemicals: Produces Bile for Fats enzymes

Gallbladder- green sac under the liver Function: Stores Bile Chemicals: BILE for fat breakdown

Pancreas-gland near stomach Function: Produces chemicals that digest proteins, carbohydrates, fats Chemicals: Lipase, Protease, Amylase Insulin- regulates Blood sugar Sodium Bicarbonate (baking soda) – neutralizes stomach acid

Digestion Animation Check out all the different types of food and what happens to them http://kitses.com/animation/swfs/digestion.swf