Bell Ringer• What you need for

class:– Pencil– Science notebook– New bell ringer sheet– Colored pencils– scissors

• The transport tube that carries chewed food to the stomach is the —

a. esophagus.b. stomach.c. intestine.d. mouth.

Bell Ringer• What you need for

class:– Pencil– Science notebook– Colored pencils– scissors

nose trachea ? lungs

• The organs that move the air from the trachea to the lungs are missing in the diagram above. What are these organs called?

a. bronchib. diaphragmc. alveolid. capillaries

The Digestive System

SC Indicator 7-3.2

Recall the major organs of the human body and their

functions within their particular body system.

SC Indicator 7-3.3

Summarize the relationships of the major body systems.

Essential Question

What are the 3 secondary organs that food does not actually travel through,

but are very important in the digestive system?

Essential Question

A wet ball of chewed up food is called a __.

Essential Question

The flap of tissue that closes across the

windpipe to keep food from entering it is

called the ___.

Essential Question

What organ produces bile?

Essential Question

What are the 3 major functions of the

digestive system?(3 words)

Essential Question

What substance must be present in the

stomach for pepsin to work best?

Essential Question

Nutrient molecules pass from the small intestine into the

bloodstream through tiny structures called

____.

Essential Question

Bile made by the liver is stored in the ___.

The Human Digestive System

What happens

when I eat pizza?

What happens when I eat pizza?

• Although it smells really good, in its current form, that pizza will not do my body much good.

• It is much too large to squeeze into my tiny cells.

• Even if I could get it into one of my cells, that cell would not be able to use it.

• What do I need to do to the pizza before I put it into my cells?

• That’s right! I need to break it down into smaller pieces.

I use my

teeth to take

that first

delicious

bite!

Your mouth is the chomping champ!

• As I lift the slice of pizza up towards my mouth, what is the first thing I do to begin breaking it down into smaller pieces?

• That's right, I bite it. • The pizza slice is too big to swallow

in one giant gulp, so I bite the tip off. • Already I have begun breaking it

down, haven’t I?

But wait!

• Now what am I doing?• I am still breaking it down into

smaller pieces.• I am squishing it, and grinding it,

and cutting it using my teeth. • Something else very important is

also happening.

Bite the pizza and chew it up!

What else is happening?

• My mouth produces a chemical called saliva, which is more commonly referred to as spit.

• Saliva is produced by my salivary glands, and is released as I begin to chew.

• It can also be released when I smell something yummy.

• Saliva has a couple of important jobs to perform.

The Job of Saliva (spit)

• First, it moistens my food. • This makes it easier to chew and

helps lubricate it so that it can travel through my body more easily.

• Saliva also contains chemicals that begin to break my food down into smaller pieces through the process of chemical digestion.

Saliva moistens food.

It also contains

chemicals that start to break

down food right away in your mouth.

Teeth cut it, grind it,

and squish it.

Saliva starts

chemically breaking down the

food.

How is food broken down?

• Now I am holding a slice of pizza in my hand with a bite missing out of it.

• In my mouth I have a small wet ball of mashed up crust, sauce, cheese, pepperoni, and saliva, called a bolus.

• So what's next?

I’ll swallow it, of course!

The Esophagus(The Waterslide of the Body)

• Uh Oh!! Here it comes. • Wait… I swallow it. • That wet ball of chewed up pizza

begins a long journey towards the cells of my body.

• At this point it is still much too big to fit inside any of my tiny cells.

• Even the smallest pieces would be far too large to do my cells any good.

The Esophagus(The Waterslide of the Body)

• After swallowing my pizza bite, it enters into my esophagus.

• The esophagus is like a long slippery waterslide.

• Muscles within my esophagus squeeze the food down towards my stomach.

The ESOPHAGUS = Food Tube

Esophagus

The esophagus carries fo

od

from th

e mouth to th

e

stomach.

EsophagusMuscles in

the esophagus p

ush

the food in the rig

ht dire

ction.

The Esophagus

• Whether I am standing up, laying down or hanging upside down, I can safely swallow a bite of food, because the muscles within my esophagus know that their job is to send food in only one direction… towards my stomach.

A Look InsideYour

Esophagus

Muscles move the food down

the esophagus

during peristalsis.

Peristalsis is when food is squeezed by muscles and pushed down

to your stomach.

The Stomach

• As that pizza bite falls into my stomach, a round muscle called a sphincter closes behind it.

• This protects the esophagus from having food or other chemicals splash back into it.

• The single pizza bite is soon joined by other bites as I continue eating.

Look at my pizza go…

What is HEARTBURN?

The Stomach (continued)

• After a few minutes my stomach is completely full.

• Because I feel full, I stop eating, and run off to do some household chores.

• As I walk the dog, dust and sweep, run the vacuum, load the washer and fold the clothes, I don’t think about the food or what it is doing inside of me, but my body does not forget about it.

• Deep within me, my body continues the process of breaking food down into smaller and smaller pieces.

The Stomach (continued)

• For the next couple of hours my stomach muscles churn and grind the food in my stomach, causing it to roll over and over again.

• Glands within my stomach release a variety of powerful chemicals which help to further break down the food within me.

Most mechanical digestion

occurs here.

The stomach muscles churn and squeeze it like clothes in

a washing machine.

The Stomach (continued)

• The two most important chemicals in my stomach are hydrochloric acid and pepsin.

• Together these chemicals break the pizza down into a slush known as chyme.

Digestive juices, like pepsin and

hydrochloric acid, help

more chemical digestion to

occur.

Mucus coats and protects the lining of

your stomach.

My Small Intestine

• Although the slushy chyme is much more broken down than the original pizza bite, the small pieces floating in the chyme are still too large to fit inside my cells.

• They must be broken down even further.

My Small Intestine

• Once the chyme is ready, a valve opens in my stomach and releases the chyme into my small intestine.

• The small intestine is where most of the digestion process takes place.

• It’s where most chemical digestion occurs.

My Small Intestine

• As the chyme enters my small intestine it is mixed with a variety of chemicals, whose job it is to further break down the pizza.

• My liver adds a liquid known as bile which helps to neutralize the acids from my stomach, so that digestion can continue to take place.

Food leaves the stomach and enters the small intestine.

As I said, most

chemical digestion

takes place here.

My Small Intestine

• By now, I am done with all my chores, have walked the dog again, and I’m sitting on the sofa watching television.

• The chyme is slowly moving further along in my small intestine.

• As it moves along, the process of digestion is almost complete.

• My small intestine is lined with tiny folds called villi.

Villi in the Small Intestine

• The muscles within my small intestine squeeze and roll the food about.

• As it sloshes around, the villi quickly absorb the nutrients from the chyme, leaving behind the materials that are not nutritious.

• So…the job of the small intestine is to absorb the nutrients from the foods we eat! Remember that.

Villi in the Small Intestine

Villiin your small

intestine give more

surface area for

nutrients to be

absorbed.

More surface area means that more nutrients can be absorbed by your

body!

The Large Intestine

• As chyme enters my large intestine, there are virtually no nutrients left.

• The job of the large intestine is to remove water from the remaining waste.

• Water is very important to my body, and it cannot afford to allow water to leave unnecessarily.

• Slowly the chyme passes through my large intestine becoming dryer and harder.

The large intestine

absorbs water into the

bloodstream.

The remaining material is readied for elimination

from the body.

The large intestine is about 1½ meters long – about as long as a

bathtub.

Small and Large

Intestines

The End of the Journey!

• Eventually, after about 24 hours, my body no longer needs what remains of that pizza.

• It has traveled from my mouth to my large intestine, getting smaller and more broken down each step along the way.

• Because all of the nutrients and water have been removed from the pizza, all that remains is to get rid of the waste that has been left behind.

The short tube at the end of the large intestine is called the

rectum.Waste material is

compressed into solid form in the rectum

The waste material, or feces, is eliminated

from the body through the anus.

The anus is a muscular opening at the end of

the rectum.

Rectum & Anus

The End of the

Journey!

The End of the Journey!

The End of the

Journey!

Let’s Review!

Organs of the

Digestive System

Organs of the

Digestive

System& Their Functio

ns

Organs of the Digestive System& Their Functions

Let’s go through these

organs again…

…and again…

…and again.

Cool Picture

Inside the human

body…organs of the

digestive system.

Our Digestive Tract

The Human

Digestive System

The Human Digestive System

Mouth

SalivaryGlands

Esophagus

Stomach

Liver

SmallIntestineLarge

Intestine

RectumAnus

SalivaryGlands

How well can you

do naming

the parts?

Digestion Animation

Let’s look on the Internet at an animated explanation of the

DIGESTIVE SYSTEM!

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter26/animation__organs_of_digestion.html

Digestion Animation

Let’s look on the Internet at an animated explanation of the

DIGESTIVE SYSTEM!

http://health.howstuffworks.com/human-body/systems/digestive/adam-200142.htm

Label the Digestive System #1

Let’s see if you can remember all of the organs of the digestive system…

http://www.neok12.com/diagram/Digestive-System-01.htm

Label the Digestive System #2

Let’s see if you can remember all of the organs of the digestive system…

again!

http://www.neok12.com/diagram/Digestive-System-01.htm

Label the Diagram

Can you name the organs of

the digestive system?

Mouth

Stomach

Pancreas

SmallIntestine

Rectum

GallbladderLarge

Intestine

Cool Demonstration of the Digestive System

I loved this demonstration…though some is a little cheesy!

Enjoy it!

http://www.neok12.com/php/watch.php?v=zX4559475700465170435873&t=Digestive-System

A Trip Through the Digestive System

Would you like to take a trip through the digestive system?

Let’s GO!

http://nature.ca/discover/exm/blddgstvsystm/index_e.cfm

The Digestive System

What is the digestive system?

Kid’s Health will help us understand!

http://kidshealth.org/kid/htbw/digestive_system.html

Salivary Gland

Throat/PharynxTeeth

Epiglottis

Esophagus

StomachLiver

Gallbladder

Begin Small Intestine

Pancreas

Large IntestineSmall Intestine

AppendixRectum

Bile Duct/Tube

Let’s see if you can do

this one.

There are a couple

tough ones.

It’s your turn to

illustrate the organs of

the digestive system.