The Digestive The Digestive SystemSystem

WhatWhat’’s really s really happening to the happening to the food that we eat?food that we eat?

Think about this…Think about this…Just like a car needs fuel to go…

…Our bodies need food to keep

working.

However, WeHowever, We’’ve got a ve got a problem…problem…

Most food that Most food that you eat is too you eat is too big and complex big and complex for your tiny for your tiny cells. Thatcells. That’’s s

when the when the Digestive Digestive

System comes System comes into play.into play.

What is Digestion?What is Digestion?

DigestionDigestion--breaks down breaks down food into food into smaller and smaller and simpler simpler substances substances that your body that your body can absorb.can absorb.

WHISPER TO YOUR NEIGHBORWHISPER TO YOUR NEIGHBOR

What What does does

DigestioDigestion do?n do?It breaks down food into smaller and simpler

substances that your body can absorb.

LetLet’’s take a journey s take a journey through our body to see through our body to see where our food travels…where our food travels…

11stst Stop…The Stop…The MOUTH!MOUTH!

What goes on in What goes on in the mouth?the mouth?

When you first eat When you first eat your food, it goes your food, it goes straight into your straight into your

mouth! The mouth and mouth! The mouth and teeth are the first teeth are the first steps in breaking steps in breaking

food down. The mouth food down. The mouth supplies chewing and supplies chewing and our tongue is used our tongue is used

for tasting.for tasting.

LetLet’’s pretend you are s pretend you are going to going to

take a great big bite of take a great big bite of an apple. an apple.

Once you take that bite…your teeth start Once you take that bite…your teeth start tearing through the apple skin and tearing through the apple skin and grind the apple into a ball of food grind the apple into a ball of food (also known as bolus). (also known as bolus).

When the apple touches your When the apple touches your tongue, your taste buds tell you tongue, your taste buds tell you it is sweet. it is sweet.

The salivary glands in your mouth The salivary glands in your mouth and throat produce a watery fluid and throat produce a watery fluid called saliva. Saliva helps to called saliva. Saliva helps to moisten and soften the bolus and moisten and soften the bolus and break it down chemically.break it down chemically.

Now that our food is all Now that our food is all chewed up… chewed up…

Our tongue moves the Our tongue moves the chewed up apple to the chewed up apple to the back of our mouth and back of our mouth and

we…we…

SWALLOW IT!SWALLOW IT!

Mouth- The teeth grind up the food.

Salivary glands in your mouth produce saliva which softens the bolus (ball of food) and breaks it down chemically.

22ndnd Stop…The Esophagus Stop…The Esophagus

What does the What does the esophagus do?esophagus do?When you When you

swallow your swallow your food, it goes food, it goes down your down your esophagus. esophagus.

Your esophagus Your esophagus is a tube that is a tube that is about 10 is about 10 inches long inches long that connects that connects your mouth to your mouth to your stomach.your stomach.

Esophagus- a tube that connects

the mouth to the stomach.

““Wait… what are Wait… what are the first two the first two organs in the organs in the digestive system? digestive system? Point to them and Point to them and tell me them.tell me them.””

The MOUTH The MOUTH and and

the ESOPHAGUS!the ESOPHAGUS!

Nice Job!Nice Job!

What comes What comes next?next?

10 seconds later…310 seconds later…3rdrd Stop…Stop…

the STOMACH!the STOMACH!

The Stomach…The Stomach…When food enters When food enters the stomach, the the stomach, the muscles in the muscles in the stomach contract stomach contract and relax to and relax to

create movement. create movement.

Then in the Then in the stomach acids stomach acids and digestive and digestive

juices transform juices transform the food into a the food into a

liquid liquid substance.substance.

Think about it this Think about it this way…way…

Think about mixing Think about mixing the ingredients to the ingredients to

make a cake. make a cake.

You take a spoon and You take a spoon and start stirring the start stirring the

ingredients ingredients creating a movement creating a movement that resembles the that resembles the contraction. It contraction. It

isnisn’’t until you add t until you add a liquid substance a liquid substance (egg/oil) that the (egg/oil) that the ingredients begin ingredients begin transforming into a transforming into a liquid substance.liquid substance.

Stomach- The walls of the stomach have

glands which produce acids and mucus. The muscles of the

stomach contract and create a movement. The muscles

squeeze and mix the bolus until it is changed into a thick liquid.

After about 4-6 hours After about 4-6 hours later of mixing and later of mixing and squeezing, the squeezing, the liquid is released liquid is released into the….into the….

44thth Stop… Stop…Small IntestineSmall Intestine

The Small IntestineThe Small IntestineOkay…Now our bolus has transformed into a liquid substance. Here in the small intestine, chemicals from the pancreas and the liver continue to mix with the bolus. The digestive juices break down the nutrients from the food into smaller, simpler forms. The nutrients are absorbed by the small intestine. The nutrients pass through the walls of the small intestine into tiny blood vessels that are transported throughout the body. food passes into the bloodstream throughthe villi, which line the small intestine walls,and are transported throughout the body.

Small Intestine- A coiled, tubular organ that

breaks down the food mixture so your body can absorb all the

nutrients through tiny hairs called villi.

WHISPER TO YOUR NEIGHBORWHISPER TO YOUR NEIGHBOR

What are What are the first the first 4 organs 4 organs in the in the

digestive digestive system?system?The mouth, esophagus, stomach, and small intestine.

But wait…what happens to But wait…what happens to the food that I couldnthe food that I couldn’’t t

digest?digest?

55thth Stop… Stop…The LARGE The LARGE INTESTINE!INTESTINE!

Large Intestine Cont.Large Intestine Cont.

The parts of the The parts of the apple that you apple that you could not digest could not digest move into the move into the large intestine. large intestine. The large The large intestine is a intestine is a thick, tubular thick, tubular organ that organ that removes removes undigested waste.undigested waste.

Large Intestine-

A thick tubular organ that removes undigested

waste.

66thth Stop…Stop…

The Rectum The Rectum

Solid waste called feces

is eliminated

from the body through the

rectum.

Rectum-

Small waste called feces is eliminated from the

body.

““Wait… what is the Wait… what is the order the organs order the organs in the digestive in the digestive system?system?””

The mouth, esophagus, The mouth, esophagus, stomach, small intestine, stomach, small intestine, large intestine, rectum.large intestine, rectum.

Think: MESSLRThink: MESSLR

Now that we know Now that we know how the Digestive how the Digestive

System works…System works…LetLet’’s put it into s put it into

action.action.