Educational worksheet on the human respiratory system, including a labeled diagram and questions about gas exchange.

Let's solve this step by step. The image is a worksheet about the human respiratory system, with two main parts:

1. Labeling the diagram of the human respiratory system.
2. Answering questions based on gas exchange and completing a paragraph.

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🔹 Step 1: Label the Diagram

We are given a list of terms to label:
- alveoli
- bronchi
- bronchiole
- diaphragm
- epiglottis
- larynx
- lung
- mouth
- nasal passage
- nostrils
- pharynx
- pleura
- trachea

Now, let’s identify where each part goes in the diagram (based on standard anatomy):

1. Nostrils – Top of the nose (entrance to nasal cavity)
2. Nasal passage – Inside the nose, behind the nostrils
3. Mouth – Below the nose, alternative air entry
4. Pharynx – Throat area; connects nose/mouth to larynx
5. Epiglottis – Flap covering the larynx during swallowing
6. Larynx – Voice box, below pharynx
7. Trachea – Windpipe, below larynx
8. Bronchi – Two main tubes branching from trachea into lungs
9. Bronchiole – Smaller branches inside lungs
10. Alveoli – Tiny air sacs at end of bronchioles (shown in inset)
11. Lung – Right and left lungs
12. Diaphragm – Muscle beneath lungs
13. Pleura – Thin membrane surrounding each lung

✔ Labels (from top to bottom):

- Nostrils
- Nasal passage
- Mouth
- Pharynx
- Epiglottis
- Larynx
- Trachea
- Bronchi
- Bronchiole
- Alveoli (in magnified circle)
- Lung
- Diaphragm
- Pleura (around lung)

> Note: "Pleura" may be labeled on the outer lining of the lung, and "diaphragm" at the base of the lungs.

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🔹 Step 2: Gas Exchange Questions

Given table:

| Gas | Inhaled | Exhaled |
|-----|--------|--------|
| O₂ | 20.71% | 14.6% |
| CO₂ | 0.04% | 4.0% |
| H₂O | 1.25% | 5.9% |

#### 1. What gas is removed from inhaled air?

➡️ Oxygen (O₂) is used by the body, so it decreases from 20.71% to 14.6%.
✔ Answer: Oxygen (O₂)

#### 2. What gases are added to inhaled air and then exhaled?

Gases that increase in exhaled air:
- Carbon dioxide (CO₂) → increases from 0.04% to 4.0%
- Water vapor (H₂O) → increases from 1.25% to 5.9%

✔ Answer: Carbon dioxide (CO₂) and water vapor (H₂O)

#### 3. Which gas shows the greatest difference in percent between inhaled and exhaled air?

Calculate differences:
- O₂: 20.71 – 14.6 = 6.11%
- CO₂: 4.0 – 0.04 = 3.96%
- H₂O: 5.9 – 1.25 = 4.65%

➡️ Largest change is oxygen (O₂)

✔ Answer: Oxygen (O₂)

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🔹 Step 3: Complete the Sentence

Fill in the blanks:

> Inspired air, rich in oxygen, enters the body through the nostrils, or mouth. It passes through the pharynx and larynx, or voice box, and into the trachea. Air then enters each lung, which branches into bronchi, and finally into the air sacs or alveoli of the lungs. The lungs are housed in the thoracic cavity that is bound on the bottom by a thin layer of muscle, the diaphragm. Each lung is covered by a very thin pleura membrane. In the alveoli, carbon dioxide is exchanged for oxygen.

✔ Final filled sentence:

> Inspired air, rich in oxygen, enters the body through the nostrils, or mouth. It passes through the pharynx and larynx, or voice box, and into the trachea. Air then enters each lung, which branches into bronchi, and finally into the air sacs or alveoli of the lungs. The lungs are housed in the thoracic cavity that is bound on the bottom by a thin layer of muscle, the diaphragm. Each lung is covered by a very thin pleura membrane. In the alveoli, carbon dioxide is exchanged for oxygen.

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✔ Final Answers Summary

#### Labeling:
Use the list above to match labels to diagram.

#### Gas Exchange:
1. Oxygen (O₂)
2. Carbon dioxide (CO₂) and water vapor (H₂O)
3. Oxygen (O₂)

#### Paragraph Completion:
As written above.

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This completes the worksheet! Let me know if you'd like a printable version or an image annotation.