chapter 2

Chapter 2How Do Parts of Living Things Work Together?

ORGANS & MOVEMENTLesson #2

OrgansStructures that carry out specific jobs as you live and grow.

Heart

Lungs

Stomach

Organs in the Human Body• What organ of the human body can you observe in this photo?• Why can’t you observe any other organs in this photo?• Why does the body need a wide variety of organs to function properly?

Moving the Human Body

Bones Muscles

Moving the Human Body

Bones are a type of organ.

The framework of bones in your body is called a skeleton.

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Moving the Human BodyBones can’t move on their own, you need

muscles for that.

• Why is it important for skeletal muscles to work in pairs?• Why might it be important to have involuntary muscles in organs like the stomach?

MOVING BLOOD AND OXYGEN

Lesson #3

BloodVeins carry blood toward the heart.

Arteries carry blood away from heart.

Blood

• How are veins and arteries alike?• How are they different?

Circulatory System Animation

• Which parts of the body receive blood from blood vessels?• Why do body parts need blood?• What happens to blood after it leaves the heart? (Let’s find out!)• What happens to blood when it is inside the capillaries?

The Heart• What happens when the heart beats?

Let’s Watch!

• Does blood travel inside the heart through one pathway, a few pathways, or many pathways?

Let’s Check!

• When blood leaves the heart, can it travel through only one pathway, a few pathways, or many pathways?

Let’s Check!

The LungsLungs Animation

• What happens to the air you breathe into your lungs? What two gases are involved?• Why is this exchange of gas important?• Why is the heart necessary for the lungs to work properly?

GETTING FOOD AND REMOVING WASTE

Lesson #4

The Digestive SystemWe all need food, but in order to use the chemical, potential energy in it we need to digest it and get rid of the parts our bodies can’t use.

To accomplish this task your body comes equipped with a digestive system.

The Digestive System

Pancreas Liver

While the pancreas and liver are part of the digestive system, food does not pass through them. Instead, both make substances that help break down food so that it can be digested.

PancreasThe Pancreas makes juices that help your body digest food.

It also helps the body use sugars.

LiverThe liver is a very large and important organ.

It makes bile that enters the small intestine and helps digestion.

Organs in Digestion• Where does the Esophagus carry food to?• What happens to food in the stomach?• Where does it go from there?• What happens to food in the small intestine?• What happens to any remaining food after it leaves the small intestine?

KidneysWhat are the purpose of kidneys?

Let’s explore!

BladderWhy is the bladder an important organ?

CONTROLLING THE HUMAN BODY

Lesson #5

The Brain• When I pick up a pencil, where in my body do I decide to do it?• How did the message to bend over and pick it up travel to my arms and legs?• What kinds of messages might begin and end inside the brain?• Why is it important for parts of the brain to keep working even when you are asleep?

Click here to explore your brain!

ReviewClick here to review body systems with an amazing video!

Review Questions