The Digestive System - mrenns.com€¦The Digestive System The digestive system has 3 main functions. To breakdown food into smaller nutrients. To absorb nutrients into the bloodstream.

The Digestive System What Happens After You Swallow?

The Digestive System The digestive system has 3 main functions.

To breakdown food into smaller nutrients.

To absorb nutrients into the bloodstream.

To eliminate wastes from the body.

From Small to Big

The food we eat is not useful immediately.

But, these are too big for our body to use.

The 3 main nutrients in food are carbohydrates, proteins and fats.

G G G G G G

They must be broken into smaller pieces.

G G G G G G G G G

sugars

amino acids

fatty acids

carbohydrates

proteins

fats

Huge, useless molecules

Small, useful molecules

G G G G G G G G G

sugars

amino acids

fatty acids

carbohydrates

proteins

fats

Huge, useless molecules

Small, useful molecules

digestion

Digestion

Digestion is the break down of food into smaller nutrients.

There are 2 kinds of digestion:

Digestion

Digestion is the break down of food into smaller nutrients.

Physically breaking food down by

cutting, tearing and slicing.

Breaking down food by using chemicals

like acid and enzymes.

e.g. teeth

Mechanical

e.g. stomach

Chemical

Digestive System Organs

mouth

esophagus

stomach liver

gall bladder

salivary glands

pancreas

small intestine

large intestine

rectum

epiglottis

1. Mouth

Digestion starts in the mouth.

Both mechanical and chemical digestion begin in the mouth.

Your teeth tear & mash food into smaller pieces.

Saliva moistens and digests food using enzymes.

Mechanical Chemical

1. Mouth

Saliva is produced by the salivary glands.

There are 3 salivary glands surrounding

the mouth.

Saliva contains enzymes that break down carbohydrates

into sugars.

Epiglottis

When you swallow, the epiglottis directs the food down the esophagus.

The epiglottis is a small flap that blocks food from

entering the trachea.

epiglottis

esophagus trachea

Choking is caused by food entering

the trachea.

2. Esophagus

Food then moves down the esophagus.

The esophagus is a muscular tube that connecting the mouth to the stomach.

Circular muscles in the esophagus push

the food downward.

3. Stomach

Digestion continues in the stomach.

Both mechanical and chemical digestion continue in the mouth.

The stomach squeezes and

churns the food.

Acid & enzymes turn food into liquid form.

Mechanical Chemical

4. Small Intestine

Food enters the small intestine in liquid form.

The small intestine finishes chemical

digestion and then absorbs nutrients

into the blood.

Other organs produce enzymes to help with chemical digestion…

Enzymes made in 3 organs help with digestion:

Makes enzymes to

digest starch and fats.

Makes an enzyme

called bile to digest fats.

Makes enzymes to

digest starch, proteins and

fats.

liver s. intestine

4. Small Intestine

pancreas

Making Enzymes

Absorption

3-5 hours after eating, food in the small

intestine is fully digested.

The small nutrients can now be absorbed into

the bloodstream.

The nutrients cross through the walls of

the intestine. blood s. intestine

The intestine is designed to help absorption.

Absorption

The small intestine has millions of tiny folds called villi that make the surface

area of the intestine much greater.

4. Large Intestine

Material entering the large intestine is mainly water and undigested food.

The lg. intestine has 2 jobs:

2. Package undigested food into waste

1. Absorb needed water from the food

5. Rectum

The rectum is a short tube below the intestine.

The rectum compacts the waste into solid

form - your poo!

When there is enough, the waste is passed from

the body through an opening called the anus.

The End

Any Questions?