NUTRITION 3 - Respiratory System worksheet - Free Printable

Let's solve the worksheet step by step and explain each answer.

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1.1. Answer the questions using the words provided in the box:

Words: *oxygen, involuntary, carbon dioxide*

#### a) What gas does human beings take in when we breathe?
We inhale _________.
✔ Answer: *oxygen*
🔹 Explanation: When we breathe in (inhale), we take in oxygen from the air. Oxygen is essential for cellular respiration, where it helps produce energy in our cells.

#### b) What gas does human beings eliminate during respiration?
We exhale _________ _________.
✔ Answer: *carbon dioxide*
🔹 Explanation: During cellular respiration, our body produces carbon dioxide as a waste product. This gas is transported back to the lungs and exhaled out of the body.

#### c) Is respiration a voluntary or involuntary movement?
It is an _________ movement.
✔ Answer: *involuntary*
🔹 Explanation: Breathing (respiration) is controlled by the brainstem and happens automatically without conscious effort. Although we can control breathing temporarily (e.g., holding breath), it is primarily an involuntary process.

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1.2. Name the organs of the respiratory system

Use the word bank:
- Nose
- Bronchioles
- Larynx
- Trachea or windpipe
- Bronchi
- Pharynx
- Lungs
- Alveolar sacs or alveoli

Now label the diagram:

Let’s go through each numbered part based on standard anatomy:

1) Nose – The entry point for air into the respiratory system.
2) Pharynx – Also called the throat; connects nose and mouth to the larynx.
3) Larynx – Commonly known as the voice box; located below the pharynx.
4) Trachea or windpipe – A tube that carries air from the larynx to the bronchi.
5) Bronchi – Two main branches from the trachea that enter the lungs.
6) Bronchioles – Smaller branches of the bronchi that lead to the alveoli.
7) Alveolar sacs or alveoli – Tiny air sacs where gas exchange occurs (oxygen enters blood, CO₂ exits).
a) Lungs – The large organs where gas exchange takes place; contain bronchi, bronchioles, and alveoli.

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✔ Final Answers:

#### 1.1.
a) We inhale oxygen.
b) We exhale carbon dioxide.
c) It is an involuntary movement.

#### 1.2. Labeling the diagram:
1) Nose
2) Pharynx
3) Larynx
4) Trachea or windpipe
5) Bronchi
6) Bronchioles
7) Alveolar sacs or alveoli
a) Lungs

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This completes the worksheet! The answers are based on basic human physiology of the respiratory system. Let me know if you'd like a printable version or further explanation!