Digestive SystemYour 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 SystemThis 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 digestionInvolves both mechanical & chemical

processes

Mechanical Process of digestionChewing and mashing food into smaller pieces

Chemical Process of digestionBreaking 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 TeethDigestion 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 IntestineFood passes from mouth to esophagusThe Esophagus is a muscular tube that pushes food

down into the stomach in a process called peristalsisPeristalsis 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 IntestineSmall 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 DigestionAssisted by 3 Important Organs

Food does NOT pass through these organs

Liver 2nd 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

digestedExcretory System is your body’s waste removal

systemProcess of removing wastes from your body is known as

excretion

http://www.youtube.com/watch?v=XF_lF3J4ZKs

The Process of ExcretionFood particles that cannot be digested move from

the small intestine to the large intestine, or colonLiquid 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 SystemKidneys- 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 SystemHave 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 eatDiarrhea (watery feces)

Food might be contaminated with bacteriaHeartburn – burning sensation in center of

chest or throat. Has nothing to do with heartResult 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 mealsChew food thoroughly. Don’t wash large pieces

downDrink 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.