Unit #5 Chapter 16 in Textbook Pages

Introduction to Digestion Organs and Organ Systems

What is Digestion?

the mechanical and chemical breakdown of complex food into simple nutrients that cells can use It is considered an open system DIGESTION IS

Two Types of Digestion Mechanical Breaking food into small pieces using Teeth Tongue Smooth muscle Chemical Breaking food into small pieces using Chemicals

Complex Food Food that is not in a form that could be used by cells

Simple Nutrients Food that is broken down to molecules that cells can absorb and use.

Levels of Organization Atom – Oxygen (O) Molecule – Water (H 2 O) Organelle - mitochondria Cell – animal cell Tissue - muscle Organ - stomach Organ System - digestive Organism - human

Six Basic Simple Food Nutrients Fats Carbohydrates Proteins Vitamins Minerals Water

What does “food” give your body Materials for growing and repairing body tissue Energy for everything you do

Carbohydrates (simple or complex) Supply quick energy to cells Sugars, glucose, starches and fiber

Fats Supply energy, but fats are usually stored Two Types Saturated – solid at room temperature Unsaturated – liquid at room temperature

Proteins (complete and incomplete) Used by cells for growth and repair Two Types Complete – animal sources Incomplete – plant sources

Vitamins Substances that help control growth and normal body function

Minerals Inorganic substances that help control growth and normal functions

Water Main compound in a living body Makes up 50-60% Needed for chemical reactions

Food Guide Pyramid A changing model

New vs Old

Updating Again MyPlate is part of a larger communications initiative based on 2010 Dietary Guidelines for Americans to help consumers make better food choices.

Food Labels Provide Nutrition Information

Nutrition information provided on food labels Nutrition Facts Ingredient List Nutrition Claims Health Claims INGREDIENTS: Whole wheat, wheat bran, sugar/glucose-fructose, salt, malt (corn flour, malted barley), vitamins (thiamine hydrochloride, pyridoxine hydrochloride, folic acid, d- calcium pantothenate), minerals (iron, zinc oxide). “Good source of fibre” “Part of a heart healthy diet…”

What food products have Nutrition Facts? Almost all prepackaged foods have Nutrition Facts. Some exceptions are: fresh fruit and vegetables, raw meat, poultry, fish and seafood; foods prepared or processed at the store: bakery items, sausage, salads; foods that contain very few nutrients: coffee beans, tea leaves, spices; alcoholic beverages.

Use Nutrition Facts … to easily compare similar foods to look for foods with a little or a lot of a specific nutrient to select foods for special diets … to make informed food choices

The Ingredient List Lists all of the ingredients for a food by weight, from the most to the least. Is a source of information for certain nutrients. Is a source of information for people with food allergies

Nutrition Claims Are regulated statements made when a food meets certain criteria. They are optional, and may be found only on some food products.

Health Claims Disease risk reduction claims

Structure and Function of the Mouth and Pharynx Human Mouth Structure

Mouth StructureFunction Mechanical Digestion Chemical Digestion Enzymes and mucus Contains Teeth Tongue

Salivary Glands StructureFunction Produce Saliva Breaks down starch into sugar Produce 1 ½ liters per day Lubricate and hold chew food together bolus

Pharynx (area) StructureFunction Swallow food Respiratory and Digestive Systems meet Area contains Epiglottis Sinuses Trachea Eustachian tubes Esophagus

Structure and Function of Organs in the Digestive System Human Digestive System

Esophagus StructureFunction To get food to the stomach by muscular “squeezing” Peristalsis Example: Tennis ball and sock

Stomach StructureFunction Temporarily store food Muscular sphincters control the flow of food Mix food with gastric juices

Gastric Juices contain Mucus Protects stomach wall Hydrochloric Acid Kills germs Aids in protein digestion Pepsin Works with HCl to digest protein

Chyme Mixture of food and gastric juice Soupy and ready for the small intestine Released when sphincter opens

Small Intestine Structure 6 meters long 3 cm across Function Finish chemical digestion To absorb nutrient molecules Divided into 3 parts Duodenum Jejunum Ileum

Pancreas (helper organ) StructureFunction Produces pancreatic juice Mixture of chemicals containing enzymes Alkaline secretion of the pancreas

Liver (helper organ) StructureFunction Produces bile Breaks up fats

Gall Bladder (helper organ) StructureFunction Storage of bile

Villi (helper structure) StructureFunction Increase surface area of small intestine Absorb simple nutrient molecules

Appendix StructureFunction Unknown May be a store house for good bacteria

Colon (Large Intestine) StructureFunction Absorb Water Vitamins Minerals Contents contain Fiber from plants Bacterial Body wastes