Digestion The chemical and mechanical process of breaking down food to release nutrients in a form your body can use
Alimentary Canal The Digestive tract
Organs of the Digestive System
Start of Digestion Mastication: chewing
Action of Saliva Salivary glands in the mouth start the chemical processes by secreting saliva: water, mucus, salts, digestive enzymes
Saliva & Nutrients Begins to break carbohydrates down into simpler sugars
Food in the Esophagus Food moves through the Esophagus by peristalsis action: A wave like muscular contraction
Digestion in the Stomach Stomach secretes gastric fluid Hydrochloric acid, Enzymes, Gastrin, and Mucus Food can take 1 to up to 7 hours to break down in the stomach
Digestion in the small Intestines Helped by: Gall bladder, Pancreas and liver Liver: Produces Bile- helps fat mix with water Pancreas: secretes an enzyme rich fluid-reduce food to smaller molecules
Absorption in the Small Intestines Nutrients are now mere molecules and can pass through the thin, intestinal walls Villi and Microvilli: each microvilli is designed to absorb specific nutrients Nutrients pass to the lymphatic system and then the circulatory system
Absorption in the large Intestines Bacterial action: complete the breakdown of any carbohydrates and indigestible fiber Digestion in motion http://www.youtube.com/watch?v=Uzl6M1YlU3w
Waters Role in Digestion Helps break down food Helps transport nutrients through the digestive tract Reabsorbed into the body in the digestive tract
Why do we burp? A burp is simply gas We swallow air with our foods The air we breathe contains nitrogen and oxygen Extra air gets forced up through the esophagus and out the mouth
Why do I throw up? Our stomach gets irritated Gets over filled Stomach back flows into the esophagus
Why do we get constipated An unhealthy diet: high sugars and starches and low fiber A lack of exercise A lack of fluid Stress
Why do we get Heartburn Heartburn: a burning feeling that rises up from the stomach towards the neck Caused by acid from the stomach getting into the esophagus Sphincter not closing well or staying closed