Page 13 - 新思维科学学生用书6 样章

1 The human body

The heart has two sides. The left side Why must the
pumps blood that contains oxygen heart pump blood around

all around the body. The right side the body?
pumps blood without oxygen to the lungs

only. The drawing of the heart near the

beginning of this section shows the flow of
blood in the heart. Remember that the left

side of the drawing shows the right side of

the heart and the right side of the drawing
shows the left side of the heart.

Blood vessels and blood

Blood is a red liquid that flows around the body. heart lungs
The blood carries food particles and oxygen to all

parts of the body. It also picks up waste products,

such as carbon dioxide, from the body and carries
them to organs which can get rid of them.

Carbon dioxide is a waste gas that the body must
get rid of. The kidneys and lungs are body organs

that also help the body get rid of waste products.

Blood moves through the body in the blood vessels.
Look at the inside of your wrist. Sometimes you can

see the blood vessels through your skin.

There are three kinds of blood vessels: blood
carrying
• arteries blood oxygen
without from the
• veins oxygen lungs
• capillaries.

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