Educational worksheet about the respiratory system with a word bank and fill-in-the-blank questions.

Problem: Fill in the blanks using the words from the box to complete the passage about the respiratory system.

#### Box of Words:
- air
- oxygen
- inhale
- exhale
- lungs
- trachea
- respiratory
- cough
- carbon dioxide
- yawn
- bronchi
- pharynx
- hiccup
- diaphragm
- water vapor
- nose
- mouth
- sneeze
- blood

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Passage with Blanks:

All animals need ____________ to make energy from food. We get this oxygen from the ____________ that we breathe. In order to get the oxygen into the blood where it can be transported to the rest of the body, the air travels through a system of organs called the ____________ system.

When you ____________, air enters the body through the ____________ or the ____________. From there it passes through the ____________, which forces air into the ____________ and food into the esophagus. The air travels down the trachea into two branching tubes called ____________ and then on into the ____________.

In the lungs, oxygen from the air enters the ____________. At the same time, the waste gas ____________ leaves the blood and then leaves the body when you ____________. Some ____________ also leaves the body when you exhale, which is why mirrors get foggy when you breathe on them. The ____________ is the muscle that controls the lungs.

It is important to keep the respiratory system clear so oxygen can keep flowing into your body. If something gets in your nose and irritates it, you ____________. If something gets in your trachea or bronchi and irritates it, you ____________. If something irritates your diaphragm, you ____________. Finally, if the brain thinks you are not getting enough oxygen, then it forces you to ____________.

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Solution:

1. All animals need ____________ to make energy from food.
- Answer: oxygen
- Explanation: Oxygen is essential for cellular respiration, which produces energy (ATP) from food.

2. We get this oxygen from the ____________ that we breathe.
- Answer: air
- Explanation: Air contains oxygen, which we inhale to supply our bodies.

3. In order to get the oxygen into the blood where it can be transported to the rest of the body, the air travels through a system of organs called the ____________ system.
- Answer: respiratory
- Explanation: The respiratory system is responsible for breathing and exchanging gases.

4. When you ____________, air enters the body through the ____________ or the ____________.
- Answer 1: inhale
- Answer 2: nose
- Answer 3: mouth
- Explanation: Inhalation brings air into the body through the nose or mouth.

5. From there it passes through the ____________, which forces air into the ____________ and food into the esophagus.
- Answer 1: pharynx
- Answer 2: trachea
- Explanation: The pharynx directs air to the trachea and food to the esophagus.

6. The air travels down the trachea into two branching tubes called ____________ and then on into the ____________.
- Answer 1: bronchi
- Answer 2: lungs
- Explanation: Bronchi branch off from the trachea and lead into the lungs.

7. In the lungs, oxygen from the air enters the ____________.
- Answer: blood
- Explanation: Oxygen diffuses from the lungs into the bloodstream.

8. At the same time, the waste gas ____________ leaves the blood and then leaves the body when you ____________.
- Answer 1: carbon dioxide
- Answer 2: exhale
- Explanation: Carbon dioxide is a waste product of cellular respiration and is expelled during exhalation.

9. Some ____________ also leaves the body when you exhale, which is why mirrors get foggy when you breathe on them.
- Answer: water vapor
- Explanation: Exhaled air contains water vapor, which condenses on surfaces like mirrors.

10. The ____________ is the muscle that controls the lungs.
- Answer: diaphragm
- Explanation: The diaphragm contracts and relaxes to facilitate inhalation and exhalation.

11. If something gets in your nose and irritates it, you ____________.
- Answer: sneeze
- Explanation: Sneezing clears irritants from the nasal passages.

12. If something gets in your trachea or bronchi and irritates it, you ____________.
- Answer: cough
- Explanation: Coughing helps expel irritants from the airways.

13. If something irritates your diaphragm, you ____________.
- Answer: hiccup
- Explanation: Hiccups occur when the diaphragm spasms.

14. Finally, if the brain thinks you are not getting enough oxygen, then it forces you to ____________.
- Answer: yawn
- Explanation: Yawning increases the intake of oxygen when the brain detects low oxygen levels.

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Final Answer:

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All animals need oxygen to make energy from food. We get this oxygen from the air that we breathe. In order to get the oxygen into the blood where it can be transported to the rest of the body, the air travels through a system of organs called the respiratory system.

When you inhale, air enters the body through the nose or the mouth. From there it passes through the pharynx, which forces air into the trachea and food into the esophagus. The air travels down the trachea into two branching tubes called bronchi and then on into the lungs.

In the lungs, oxygen from the air enters the blood. At the same time, the waste gas carbon dioxide leaves the blood and then leaves the body when you exhale. Some water vapor also leaves the body when you exhale, which is why mirrors get foggy when you breathe on them. The diaphragm is the muscle that controls the lungs.

It is important to keep the respiratory system clear so oxygen can keep flowing into your body. If something gets in your nose and irritates it, you sneeze. If something gets in your trachea or bronchi and irritates it, you cough. If something irritates your diaphragm, you hiccup. Finally, if the brain thinks you are not getting enough oxygen, then it forces you to yawn.
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Boxed Final Answer:
\boxed{oxygen, air, respiratory, inhale, nose, mouth, pharynx, trachea, bronchi, lungs, blood, carbon dioxide, exhale, water vapor, diaphragm, sneeze, cough, hiccup, yawn}