Systems Review Notecards

1. What is a system? 2. What are the three

components of a system?

NotecardsPeristalsis, mechanical digestion, chemical digestion, digestive system, absorption

System

3 Components of a System

Front of card: word Back of card: definition or description

A system is …

Draw the web fromTuesday’s class

CAN WE EAT UPSIDE DOWN? HTTP://WWW.YOUTUBE.COM/WATCH?V=R97SFXDV6OW

On the way to the stomach: the esophagus - After being chewed and swallowed, the food enters the esophagus. The esophagus is a long tube that runs from the mouth to the stomach. It uses rhythmic, wave-like muscle movements (called peristalsis) to force food from the throat into the stomach. This muscle movement gives us the ability to eat or drink even when we're upside-down.

What do you think? Can they eat upside down?

Make a hypothesis!

How do you think food moves through the digestive tract?

What do you think happens to the food as it moves back through the digestive tract?

http://www.whfoods.com/genpage.php?tname=faq&dbid=16#digestion

Animation of Digestion

What is the FUNCTION (PURPOSE) OF the Digestive SYSTEM?

DigestionDefinition• Digestion is the breaking down of food into

smaller and simpler substances

– Mechanical digestion and Chemical digestion do this in different ways

DigestionDefinition• MECHANICAL (physical) digestion– breaking down of food into smaller pieces– involves: chewing, grinding, churning

• CHEMICAL digestion– Breaking down of food into simpler substances

(building blocks)– involves: enzymes

• ABSORPTION– Broken down food gets from digestive tract into

the body (blood)

Smaller pieces allow for more areas of contact for enzymes and digestive juices to act on speeding up chemical digestion

MECHANICAL

CHEMICAL

Where do you think most of

the absorption takes place?

Absorption

passage of molecules into body's interior &passage throughout the body

TIME FOR PERISTALSIS EXPERIMENT!

But what is peristalsis and how do we even say that word???

Peristalsis is the involuntary waves of muscle contraction that push the food through the esophagus towards the stomach.

Hmm… I wonder what we are doing in our experiment?

Observations• Look and record what you see and do. Describe in words

and diagrams.– Top of the tube– Tube– Food particles– Fingers– Bottom of the tube

• Word choices: mouth, esophagus, food particles, peristalsis, stomach, enzyme, teeth, saliva, digestion, mechanical digestion, chemical digestion, epiglottis, chew, churn, cut

ALWAYS OBSERVE SAFETY RULES! CLEAN UP WHEN FINISHED!