Digestive System Your body needs fuel to operate Just like a car, train, or airplane needs fuel to operate The body system that converts fuel to usable energy is your Digestive System This system also helps control the elimination of used- up fuel in the form of wastes. The process of changing food into material the body can use is called digestion Involves both mechanical & chemical processes

Mechanical Process of digestion Chewing and mashing food into smaller pieces Chemical Process of digestion Breaking food down into particles with digestive enzymes Enzymes are proteins that effect the many body processes. Digestive Enzymes speed up the breakdown of food.

The Mouth and Teeth Digestion starts in the mouth Teeth tear and grind food into small pieces (Mechanical) Taste buds on your tongue sense flavor & mouth produces saliva (chemical) Saliva is a fluid made by the salivary glands that moisten and softens food, making it easier to swallow. Saliva also contains enzymes that help break down food

Stomach & Small Intestine Food passes from mouth to esophagus The Esophagus is a muscular tube that pushes food down into the stomach in a process called peristalsis Peristalsis is a series of involuntary waves that carry food particles along. Stomach Food continues to be broken down Glands in stomach wall release gastric juices, a blend of hydrochloric acid and enzymes. (chemical) Hydrochloric acid is strong enough to break down metal Stomach has protective lining that protects this powerful acid from digesting itself

Stomach and Small Intestine (cont.) Stomach serves as a temporary storage area for food. Some food remains in stomach for as long as 4 hours Most digestion occurs in Small Intestine Small intestine is a coiled, tube like organ that is about 20 feet long. Here nutrients separate from the bulk of the food Nutrients then enter the bloodstream and travel to the body cells where they are used for growth, energy, and repair.

Organs That Aid Digestion Assisted by 3 Important Organs Food does NOT pass through these organs Liver 2 nd largest organ in body Produces Bile, a substance that helps break down fats Gallbladder Stores Bile and releases it into small intestine as needed Pancreas Makes additional digestive enzymes that are released directly into small intestine. Produces Insulin to help glucose to be absorbed into the body cells Diabetes is a disorder of the pancreas. Pancreas produces too little or no insulin

Excretory (Urinary) System Once all nutrients are extracted from food, all that remains is liquid and solid waste. Body wastes consist of food materials that can NOT be digested Excretory System is your body’s waste removal system Process of removing wastes from your body is known as excretion

The Process of Excretion Food particles that cannot be digested move from the small intestine to the large intestine, or colon Liquid waste is either absorbed in colon, released through pores in skin (perspiration), or sent to the kidneys Kidneys are organs that filter water and dissolved wastes from the blood and help maintain proper levels of water and salts in the body Waste materials filtered out by the kidneys leave the body as urine Solid waste products that remain are called feces and leave the body through the anus

Parts of the Excretory System Kidneys- Main organs, remove liquid waste (urea) from the blood Ureters- The tubes that carries urine from the kidney to the bladder Bladder- Stores liquid waste before it leaves the body Urethra- The tube that releases liquid waste (urine) from the body

Parts of the Excretory System

Problems of Digestive & Excretory System Have you ever overeaten or ate too fast? This discomfort is called Indigestion Indigestion is body’s way of telling you to eat slowly and control amount you eat Diarrhea (watery feces) Food might be contaminated with bacteria Heartburn – burning sensation in center of chest or throat. Has nothing to do with heart Result of stomach acids flowing backward into esophagus

Taking Care of Your Digestive and Excretory Systems Eat a variety of healthy foods. Choose low-fat & high fiber foods from all food groups. FRUITS & VEGGY’S Don’t rush meals Chew food thoroughly. Don’t wash large pieces down Drink plenty of water!! Water is good for digestive system, drink 6 to 8 ounce glasses a day. Wash hands regularly. Before preparing or eating food wash hands with soap & water. Always wash after using the restroom.