Educational worksheet on the human respiratory system, featuring a labeled diagram and a table on 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 respiratory system.
2. Answering questions based on gas exchange and completing sentences.

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✔ Part 1: Label the Diagram

We are given a list of terms to label on the diagram:

Terms:
- 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
2. Nasal passage – inside the nose
3. Mouth – below the nose
4. Pharynx – behind the mouth and nasal cavity (throat)
5. Epiglottis – flap that covers the larynx when swallowing (just above the larynx)
6. Larynx – voice box, below the pharynx
7. Trachea – windpipe, below the larynx
8. Bronchi – two large tubes branching from the trachea into the lungs
9. Bronchiole – smaller branches within the lungs
10. Alveoli – tiny air sacs at the end of bronchioles (shown in the magnified circle)
11. Lung – large organ on each side
12. Diaphragm – dome-shaped muscle under the lungs
13. Pleura – thin membrane covering the lungs (shown as outer lining of lungs)

> 🔹 Labeling guide (from top to bottom):

- Top left: Nostrils
- Inside nose: Nasal passage
- Mouth: Mouth
- Throat area (behind mouth/nose): Pharynx
- Below pharynx: Larynx
- Just above larynx: Epiglottis
- Long tube down: Trachea
- Branches into lungs: Bronchi
- Smaller branches inside lung: Bronchiole
- Tiny sacs (in magnified view): Alveoli
- Large organs: Lung
- Under lungs: Diaphragm
- Outer lining of lungs: Pleura

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✔ Part 2: Gas Exchange Questions

Table:
| Gas | Inhaled | Exhaled |
|----------------|---------|---------|
| Oxygen (O₂) | 20.71% | 14.6% |
| CO₂ | 0.04% | 4.0% |
| Water (H₂O) | 1.25% | 5.9% |

#### Question 1: What gas is removed from inhaled air?

✔ Oxygen (O₂) — it decreases from 20.71% to 14.6%, meaning the body uses it.

> Answer: Oxygen (O₂)

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

Gases increase in exhaled air:
- CO₂ increases from 0.04% → 4.0%
- Water vapor increases from 1.25% → 5.9%

So, carbon dioxide (CO₂) and water (H₂O) are added.

> Answer: Carbon dioxide (CO₂) and water (H₂O)

#### Question 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%

➡️ Oxygen has the largest change (6.11%)

> Answer: Oxygen (O₂)

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✔ Complete the Sentences

> "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 lung. 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 (Key Parts):
- Nostrils
- Nasal passage
- Mouth
- Pharynx
- Epiglottis
- Larynx
- Trachea
- Bronchi
- Bronchiole
- Alveoli
- Lung
- Diaphragm
- Pleura

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

#### Sentence Completion:
> 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 lung. 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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