The Human Body Inside and Out:

THE DIGESTIVE SYSTEM

Ridgeview Elementary

S. Slater

Roughly How It Looks

• Liver•

Esophagus•

Stomach•

Large Intestine•

Small Intestine

Structure of the Digestive System

• Includes the teeth, tongue, salivary glands, esophagus, stomach, small intestine, and large intestine.

• Muscles are used to open valve-like openings from organ to organ (like stomach to small intestine).

Gray’s Anatomy

Gray994

Mouth

• STRUCTURE– Mouth contains teeth, salivary gland, and tongue.

• FUNCTION– The teeth chew food, saliva (from salivary gland)

softens it up, and then, when sufficiently broken down, the tongue moves food to the back of the mouth to be swallowed.

Esophagus

• Structure• Long tube lined with muscles connecting mouth

with stomach.

• Function• Pushes food from throat to stomach. Acts only

as a passageway; it does NOT break down food.

http://upload.wikimedia.org/wikipedia/commons/4/43/Gray1224.png

Mouth

Esophagus

Stomach

Small Intestine

LiverLarge Intestine

ToiletBlood

Stream

StomachFrom Wikipedia

• Can hold 1 Litre of Food after eating, but can expand to over 4 Litres if necessary!

Stomach Cont.

• Structure– Soft organ that fills with gastric juice to break down

food to prepare for the absorption of nutrients at a later stage. The stomach does NOT absorb nutrients.

• Function– The stomach is intended to break down food and

allow fat to be digested more easily. It kills bacteria entering the system. It does not absorb nutrients.

Small Intestine

• Structure:– Connect from stomach to large

intestine. Muscles move food along the tract.

– Yours might be 4-5 metres, or 12-15 feet! Four times your height!

• Function:– Absorbs nutrients from food.

Large Intestine

• Structure– Shorter than small intestine—1.5-2.5 metres.– Also muscle lined to allow food to move along the

tract.

• Function– To absorb water and eliminate waste that was not

absorbed by the small intestine.

Liver

• Produces Bile to help break down fats.

• Breaks down good and bad substances in the body to be eliminated or used. (Good: insulin. Bad: Toxins)

• Gray’s Anatomy

Interrelated

With the Muscular System:– The muscular system pushes food through

the digestive tract.– It also opens and closes the valves to each

organ.– The digestive system absorbs nutrients

from food that can be converted to energy to power the muscles.

Interrelated

The Circulatory System:

The digestive system removes nutrients from food which can then be put in the blood stream and delivered to the body for energy.

Interrelated

Skeletal System:

Removes, among other things, calcium from food, which is essential for the strength of bones.

Interrelated

Respiratory:

Provides the diaphragm muscle with energy so that it can operate to inflate and deflate the lungs.

The respiratory system provides oxygen which is needed to be combined with nutrients for muscles to use as energy.

Assignment• Imagine you have been eaten alive by a

giant! As a paragraph or story, describe the steps of the digestion process as thoroughly and graphically as possible. What fate awaits you?