Lungs Diagram - Human Lungs Anatomy - Free Printable

Let's solve the worksheet step by step.

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1. Label the parts of the respiratory system

We are given a diagram with numbered labels (1 to 8). Let’s identify each part based on its position in the human respiratory system:

- 1: Nose – This is the external opening where air enters.
- 2: Nasal cavity – The space inside the nose where air is filtered, warmed, and moistened.
- 3: Larynx – Also known as the voice box, located below the throat.
- 4: Trachea – The windpipe that connects the larynx to the bronchi.
- 5: Right lung – One of the two main organs for gas exchange.
- 6: Bronchi – The large tubes branching from the trachea into the lungs.
- 7: Bronchioles – Smaller branches of the bronchi within the lungs.
- 8: Diaphragm – The muscle beneath the lungs that helps in breathing.

So, fill in the blanks as follows:

1. Nose
2. Nasal cavity
3. Larynx
4. Trachea
5. Right lung
6. Bronchi
7. Bronchioles
8. Diaphragm

> Note: Some diagrams may label "6" as left bronchus or just bronchi, and "7" as alveoli if it points to tiny sacs. But here, since it shows branching tubes, bronchioles is correct. If it were the alveoli, it would be shown as tiny clusters. Based on standard labeling, bronchioles fits best.

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2. Complete the text about the process of respiration

Use the words provided:
- Breathe out
- Breathe in
- Blood
- Trachea
- Air
- Nose
- Bronchi
- Carbon dioxide
- Lungs
- Oxygen
- Nostrils

Now, let's complete the paragraph logically:

> 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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✔ Final Answer:

#### Part 1: Labeling
1. Nose
2. Nasal cavity
3. Larynx
4. Trachea
5. Right lung
6. Bronchi
7. Bronchioles
8. Diaphragm

#### Part 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.

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🔍 Explanation:

- Respiratory System Pathway: Air enters via nostrils → nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli (in lungs).
- In the alveoli, oxygen diffuses into the blood, and carbon dioxide (waste gas) moves from blood into alveoli to be exhaled.
- The diaphragm contracts during inhalation and relaxes during exhalation, helping move air in and out.

This completes both tasks accurately!