B

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A

N

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Teacher Notes

Notes can be taken from this PPT on notebook paper.

Certain slides have a leading question in red. The red questions indicate that notes on the data that would answer the question should be taken.

B

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A

N

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E

The Body in Balance

Maintains constant body temperature

Maintains the level of glucose in the blood

Maintains the level of salt, water and sugar in the blood

C6H12O6

B

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L

A

N

C

E

So…..

What do we call this maintenance of a balanced internal environment?

Homeostasis

What is homeostasis?

B

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N

C

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4 Major Themesin Maintaining Balance

These 4 major themes are interrelated to help your body maintain homeostasis:

• Feedback loops

• Structure and function

• Division of labor

• Interdependence of organ systems

What four themes help maintain homeostasis?

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Feedback Loops

How does the thermostat in your home maintain a constant temperature?

B

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N

C

E

Feedback Loops

Thermostat shuts off heater

Room temperature

falls

Thermostat activates

heater

Warm air is produced

Room temperature

rises

Thermostat feedback loop

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A

N

C

E

Feedback Loops

What happens to your body when you run outside in 100o temperature?

B

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C

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Feedback Loops How does this happen?

Blood vesselsin skindilate

Sensors in the brain and skin detecta change in body temperature

Sweat glandsrelease more

sweat

Body temperatureregulates

stimulus

response

This is a stimulus-response

Hormone message sent

B

A

L

A

N

C

E

Feedback Loops

A feedback loop is a stimulus-response action.

An environmental change (the stimulus) produces a reaction (response) to put the environment back into balance (homeostasis).

What is a feedback loop?

B

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L

A

N

C

E

Feedback LoopsSo….What are some of the things

that feedback regulates?

Feedback systems regulate:

• Blood sugar (glucose)

• Salt content in blood

• Hormone production

• Blood pressure

• Ion content in blood

• Water content in blood

B

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L

A

N

C

E

Structure and Function

TRY THIS! Put a rubber band around your

hand so that the thumb cannot be used. Pick up your textbook and hand it to the student next to you.

Now - pick up a penny without going to the edge of the desk or putting the penny up against something.

B

A

L

A

N

C

E

Structure and Function

TRY THIS! Continue to not use

the thumb. Try to unscrew a lid from a jar.

Pick up your pencil and write your name without using your thumb.

B

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L

A

N

C

E

Structure and Function

Why are these harder to do without the thumb?

What are some other activities that would be difficult without your thumb?

B

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N

C

E

Structure and Function

How is the structure of your thumb related to its function?

B

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N

C

E

Structure and Function

One of these represents an original native of Africa.

One of these represents an original native of Alaska.

Which is which and why?

B

A

L

A

N

C

E

Structure and Function What is the function

of plant leaves?

Why are these leaves shaped differently?

Maple leaf

Conifer

Cactus

B

A

L

A

N

C

E

Structure and Function

The dolphin and the fish are unrelated organisms.

Why do they have similar structures?

Mammal - dolphin

Fish – Queen snapper

B

A

L

A

N

C

E

Structure and Function

The shape (structure) of something affects how it works (function).

What is meant by structure is related to function?

B

A

L

A

N

C

E

Division of Labor

How many people does it take to build a building?

B

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L

A

N

C

E

Division of Labor

You would need:• Architect• Construction workers• Foreman• Plumbers• Electricians• Painters

Why do you need all of these people?

B

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L

A

N

C

E

Division of Labor

Why do you need so many different parts to digest your food?

B

A

L

A

N

C

E

Division of Labor

What do your teeth do for you?

B

A

L

A

N

C

E

Division of Labor

Esophagus

Why do you need an esophagus?

B

A

L

A

N

C

E

Division of Labor

Does the stomach do anything special for you?

B

A

L

A

N

C

E

Division of Labor

Could you live without your small intestine?

Why?

B

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L

A

N

C

E

Division of Labor

Your body systems are divided into different parts.

Each part has its own special function.

This is called a Division of Labor.

What is division of labor?

B

A

L

A

N

C

E

Interdependence of Body Systems

REMEMBER . . .

All the body systems work together to maintain homeostasis.

B

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E

Interdependence of Body Systems

What systems need to work together in order for you to write your name on a sheet of paper?

B

A

L

A

N

C

E

Interdependence of Body Systems

What systems need to work together so you can get energy from the food you eat?

B

A

L

A

N

C

E

Interdependence of Body Systems

What would happen if . . .?

You tried to move your leg with a broken femur?

You had too few red blood cells?

B

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N

C

E

Interdependence of Body Systems

All the body systems rely on each other in order to function correctly.

If one system fails to work, every system will be affected.

This shows the interdependence of all the systems.

What is interdependence of body systems?

B

A

L

A

N

C

E

Let’s review:

Explain homeostasis and why it is important.

Explain feedback loops and give examples.

Why is structure related to function? Why is surface area a part of structure?

What does division of labor mean? Why is it important for all of your

body systems to work together?