Lesson 5


Lesson 5 Part 1

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A human body contains more than 200 bones. The largest bone is the thighbone, and the smallest is the one in the ear.
Bones support and protect the various organs of the body, but we need muscles in order to move it. Muscles are joined to the bones at the ends. When the muscle works, it contracts and pulls the bone to move a body part. The point where two bones meet is called a joint.
One of the most important bones that do not move is the skull. It covers the brain in order to protect it from damage.
Muscles are not always used to move bones. The muscles of the stomach and intestines move by themselves to digest food. The muscles of your heart move to pump blood.

Lesson 5 Part 1-1

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A human body contains more than 200 bones.

Lesson 5 Part 1-2

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The largest bone is the thighbone, and the smallest is the one in the ear.

Lesson 5 Part 1-3

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Bones support and protect the various organs of the body.

Lesson 5 Part 1-4

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But we need muscles in order to move it.

Lesson 5 Part 1-5

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Muscles are joined to the bones at the ends.

Lesson 5 Part 1-6

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When the muscle works.

Lesson 5 Part 1-7

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It contracts and pulls the bone to move a body part.

Lesson 5 Part 1-8

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The point where two bones meet is called a joint.

Lesson 5 Part 1-9

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One of the most important bones that do not move is the skull.

Lesson 5 Part 1-10

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It covers the brain in order to protect it from damage.

Lesson 5 Part 1-11

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Muscles are not always used to move bones.

Lesson 5 Part 1-12

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The muscles of the stomach and intestines move by themselves to digest food.

Lesson 5 Part 1-13

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The muscles of your heart move to pump blood.

Lesson 5 Part 2

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When the heart pumps blood, it circulates around the body through blood vessels.
There are two main routes for blood to circulate. One is through the lungs, where it takes in oxygen and releases carbon dioxide. The other is the route which carries blood around the body. While blood is circulating through the body, it delivers oxygen and nutrients to the body cells and receives waste substances from them, such as carbon dioxide or ammonia.
Blood consists of red cells, white cells, platelets, and a liquid component called plasma. Red blood cells contain a red-colored protein called hemoglobin, which combines with oxygen. White blood cells work as part of the immune system, in which they protect your body against infectious organisms and foreign substances.

Lesson 5 Part 2-1

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When the heart pumps blood, it circulates around the body through blood vessels.

Lesson 5 Part 2-2

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There are two main routes for blood to circulate.

Lesson 5 Part 2-3

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One is through the lungs, where it takes in oxygen and releases carbon dioxide.

Lesson 5 Part 2-4

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The other is the route which carries blood around the body.

Lesson 5 Part 2-5

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While blood is circulating through the body.

Lesson 5 Part 2-6

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It delivers oxygen and nutrients to the body cells.

Lesson 5 Part 2-7

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And receives waste substances from them.

Lesson 5 Part 2-8

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Such as carbon dioxide or ammonia.

Lesson 5 Part 2-9

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Blood consists of red cells, white cells, platelets, and a liquid component called plasma.

Lesson 5 Part 2-10

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Red blood cells contain a red-colored protein called hemoglobin, which combines with oxygen.

Lesson 5 Part 2-11

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White blood cells work as part of the immune system.

Lesson 5 Part 2-12

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In which they protect your body against infectious organisms and foreign substances.

Lesson 5 Part 3

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The food we eat is broken down into other substances that our body can absorb as nutrients. This is called digestion. When you eat food, you chew it with your teeth in your mouth. The food will become soft and juicy by being chewed and mixed with a juice called saliva, which contains several enzymes to change starch into glucose.
When you swallow the food, it passes through your gullet, the stomach and intestines. The stomach and the small intestine produce a variety of digestive juices to break down the food into nutrients. The nutrients are absorbed into the blood while the food is being digested in the small intestine.
The last part of the digestive system is the large intestine, where water from the food is absorbed. Feces, the waste that you were unable to digest, will finally come out of the anus.

Lesson 5 Part 3-1

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The food we eat is broken down into other substances that our body can absorb as nutrients.

Lesson 5 Part 3-2

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This is called digestion.

Lesson 5 Part 3-3

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When you eat food, you chew it with your teeth in your mouth.

Lesson 5 Part 3-4

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The food will become soft and juicy by being chewed and mixed with a juice called saliva.

Lesson 5 Part 3-5

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Which contains several enzymes to change starch into glucose.

Lesson 5 Part 3-6

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When you swallow the food, it passes through your gullet, the stomach and intestines.

Lesson 5 Part 3-7

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The stomach and the small intestine produce a variety of digestive juices.

Lesson 5 Part 3-8

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To break down the food into nutrients.

Lesson 5 Part 3-9

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The nutrients are absorbed into the blood while the food is being digested in the small intestine.

Lesson 5 Part 3-10

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The last part of the digestive system is the large intestine.

Lesson 5 Part 3-11

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Where water from the food is absorbed.

Lesson 5 Part 3-12

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Feces, the waste that you were unable to digest.

Lesson 5 Part 3-13

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Will finally come out of the anus.