The respiratory system worksheet - Free Printable

Let's solve each part of this worksheet step by step.

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1. Write the parts of the respiratory system.

We are given a diagram of the human respiratory system with four blank boxes pointing to different parts. Based on standard anatomy, here’s what each label should be:

- Top left box (pointing to the nose): Nose
- Bottom left box (pointing to the trachea): Trachea
- Top right box (pointing to the mouth): Mouth
- Bottom right box (pointing to the lungs): Lungs

> ✔ So, the labels are:
> - Nose
> - Mouth
> - Trachea
> - Lungs

*(Note: Sometimes the mouth is not shown in diagrams, but since it's labeled here, we include it. The trachea connects the throat to the bronchi and lungs.)*

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2. Complete the text about the process of respiration. Use the words below.

Words provided:
- AIR
- LUNGS
- TRACHEA
- NOSE
- NOSTRILS
- OXYGEN
- BRONCHI
- CARBON DIOXIDE
- BLOOD
- BREATHE OUT

Now fill in the blanks:

> First, air enters through our nostrils and nose.
> The air goes down through the trachea and the bronchi.
> The air enters in the lungs.
> Oxygen (O₂) passes into the blood.
> Carbon dioxide (CO₂) leaves our body when we breathe out.

✔ Completed sentence:

> First, air enters through our nostrils and nose.
> The air goes down through the trachea and the bronchi.
> The air enters in the lungs.
> Oxygen (O₂) passes into the blood.
> Carbon dioxide (CO₂) leaves our body when we breathe out.

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3. True or false?

Let’s evaluate each statement:

#### 1. The respiratory system is made up of oxygen, nose, nostrils and lungs.
✘ FALSE
> Reason: Oxygen is a gas, not a part of the *system*. The respiratory system includes organs like the nose, nostrils, trachea, bronchi, lungs, etc. Oxygen is what the system processes, not a physical part.

#### 2. The respiratory system takes oxygen (O₂) and releases carbon dioxide (CO₂)
✔ TRUE
> This is correct. During respiration, we inhale oxygen and exhale carbon dioxide.

#### 3. The oxygen passes into the blood.
✔ TRUE
> In the lungs, oxygen diffuses from the alveoli into the bloodstream.

#### 4. Air enters in our body through our lungs.
✘ FALSE
> Air enters through the nose or mouth, then travels through the trachea and bronchi to reach the lungs. The lungs don’t "take in" air directly — they are the destination.

#### 5. The air goes down through the lungs to the bronchi.
✘ FALSE
> This is backwards. Air goes from the trachea → bronchi → lungs. The bronchi branch off from the trachea and lead into the lungs, not from the lungs to the bronchi.

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✔ Final Answers:

#### 1. Label the diagram:
- Top left: Nose
- Bottom left: Trachea
- Top right: Mouth
- Bottom right: Lungs

#### 2. Fill in the blanks:
> First, air enters through our nostrils and nose.
> The air goes down through the trachea and the bronchi.
> The air enters in the lungs.
> Oxygen (O₂) passes into the blood.
> Carbon dioxide (CO₂) leaves our body when we breathe out.

#### 3. True or False:
1. FALSE
2. TRUE
3. TRUE
4. FALSE
5. FALSE

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