digestive tract

Lesson 1: Human Digestive System

Foundation ScienceSC 22101

What is Digestion?

What is Digestion?

Digestion is food traveling through your body.

Digestion is food traveling through your body.

•Food starts in a form the body can’t use.•Food is broken down into smaller molecules

your body can use – that is digestion.

What is Digestion?

Digestive Tract

Digestive Tract

Digestive tract is the path the food follows.

Digestive Tract

Digestive tract is the path the food follows.

Path food follows in the digestive tract:1) Mouth No longer voluntary2) Esophagus3) Stomach4) Small Intestine5) Large Intestine6) Rectum

Digestive Tract: The Path Food Follows

The Digestive Tract: The Mouth

1) Mouth – food starts in the mouth and is broken down into pieces by teeth.

-Saliva makes the food more slippery and easier to swallow.-Saliva in the mouth has enzymes that help to break food into

smaller pieces.

Enzymes make chemical reactions go faster.

The mouth is the LAST place you have control of the food.

The Digestive Tract: Esophagus

The Digestive Tract: Esophagus

2) Esophagus – food goes from the mouth to the esophagus. Muscles in the esophagus help to move the food toward the stomach.

The Digestive Tract: Esophagus

Esophagus

2) Esophagus – food goes from the mouth to the esophagus. Muscles in the esophagus help to move the food toward the stomach.

The Digestive Tract: Stomach

The Digestive Tract: Stomach

3) Stomach – food is broken down more in the stomach by more enzymes and stomach acid .

The Digestive Tract: Stomach

3) Stomach – food is broken down more in the stomach by more enzymes and stomach acid .

The Digestive Tract: Stomach

Stomach

3) Stomach – food is broken down more in the stomach by more enzymes and stomach acid .

The Digestive Tract: Small Intestine

4) Small Intestine – where most of the nutrients from your food is absorbed . Your small intestine is about 6 or 7 meters long!

The Digestive Tract: Small Intestine

Small Intestine

4) Small Intestine – where most of the nutrients from your food is absorbed . Your small intestine is about 6 or 7 meters long!

The Digestive Tract: Small Intestine

Small Intestine

4) Small Intestine – where most of the nutrients from your food is absorbed . Your small intestine is about 6 or 7 meters long!

Inside the Small Intestine

Inside the Small Intestine

These are Small Intestine Villi

Inside the Small Intestine

These are Small Intestine Villi

VilliVilli create a lot of area so they can absorb nutrients from food.

Small intestine is where most of the nutrients from your food is absorbed into your body.

Villi

The Digestive Tract: Large Intestine

5) Large Intestine – absorbs water from the food. The large intestine is about 1.5 meters long. The large intestine and colon are the same thing.

The Digestive Tract: Large Intestine

Large Intestine

5) Large Intestine – absorbs water from the food. The large intestine is about 1.5 meters long. The large intestine and colon are the same thing.

The Digestive Tract: Large Intestine

Large Intestine

5) Large Intestine – absorbs water from the food. The large intestine is about 1.5 meters long. The large intestine and colon are the same thing.

The Digestive Tract: Rectum

6) Rectum– Stores feces.Feces is made of the parts of food your body did not use.

The Digestive Tract: Rectum

Rectum

6) Rectum– Stores feces.Feces is made of the parts of food your body did not use.

The Entire Digestive Tract is about 9 meters!

It takes your body from 24 to 72

hours to digest food.

Review

Review

Video…

1) What do you think the things are in the background of this slide?2) Name two places in your body where food is broken down into smaller parts. 3) What does the large intestine do?4) Where does most of the nutrients for your body get absorbed from? 5) What are the things that absorb nutrients in the small intestine called?6) Name 2 things you think saliva (spit) does to help digestion.7) Why does the small intestine need a lot of surface area?8) My mom used to always tell me to chew my food well before I went to play. Why do you

think she told me to do that?9) Name the 6 steps of the digestive tract in the right order. Try to do it without your

notes!!10) Your mouth has things called “salivary glands” in it. Can you guess what is the job of your

salivary glands?11) Draw the entire DIGESTIVE TRACT in your notebook. Use a different color for each of the

six parts. 12) Tell me what digestion is in your own words.13) Do you think the large intestine has villi in it? Why or why not? 14) Watch the artistic animation by Fritz Kahn again:

a) What part is missing from the digestive tract? b)What sprays the food as it enters the intestine? c)Why do you think the man waits before he releases food from the stomach?

Questions