Human DigestionScience 7

by: Mr. Rockensies

Aim: How does the digestive system break down food into nutrients?

Do Now: How many feet does your food travel through the digestive system?

HW: Worksheet

The Stormy Sea

“Then, the valve to the stomach opens and pizza mush lands in your stomach!”

“The small intestine looks like a strange underwater world filled with things that resemble small finger-like cactuses.”

“A glorious, if slightly stinky, journey, don't you think?”

Name the term used to describe the muscular contraction that pushes your food down the esophagus and into the stomach.

Describe the role that mucus plays in the stomach.

Determine the 5 steps that food takes as it travels through the digestive system.

In-class Exercises

peristalsis

Acts as a liner, protecting the stomach from acid burns

1)Eat the food2)Food enters stomach and is further digested by

acid3)Nutrients are absorbed by the small intestine4)Waste not absorbed has water taken out by large

intestine5)Waste is removed from the body

Eat/Ingest

In-class Exercises

What is digestion?

EDDiEE

D

Di

E

Diffusion

Digestion Eliminate/ Egest

The breakdown of food so that it can be absorbed

You chew food with your teeth, breaking it down into smaller pieces. Saliva breaks down starch molecules into

simple sugars.

The esophagus pushes the food down to the stomach

using peristalsis. The stomach fills with acid and contracts to

mix the food and acid.

After the stomach, the food enters the small intestine and is mixed with juices filled with

enzymes that further break down food to be absorbed by

villi

Food then travels to the colon, or large intestine, where it is

dehydrated. The water is removed and the remaining waste is then pushed out of

the body by the rectum through the anus

In-class Exercises

How is food broken down?

a) physical changes

b)chemical changes

Food is broken down mechanically – chewing, mixing, grindingEx: Teeth chewing, stomach churning

Food is mixed with acids and digestive juices containing enzymes to further break down food and release nutrients for absorption

1) E - eat/ingest

2) D - digest

3) Di - diffusion

4) E - eliminate/egest

Hypothesize what might happen if H2O was not removed during the final stages of digestion in the large intestine.

Mouth, teeth, salivary glands, tongue, esophagus

In-class Exercise

s

Stomach, pancreas, liver, gall bladder, small intestine

Small intestine (villi), large intestine

Large intestine, rectum, anus