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, cells produce 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 happens automatically without conscious control—our brainstem regulates it. Although we can consciously hold our breath or breathe faster, normal breathing is involuntary.

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1.2. Name the organs of the respiratory system.

Here’s the diagram with labeled parts:

Let’s identify each numbered part based on the anatomical structure shown:

1) Nose – The entry point for air into the respiratory system.
2) Pharynx – Also known as the throat; air passes through here after the nose.
3) Larynx – Commonly called 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 each lung.
6) Bronchioles – Smaller branches of the bronchi that lead to the alveoli.
7) Alveolar sacs or alveoli – Tiny air sacs in the lungs where gas exchange occurs.
a) Lungs – The large organs where oxygen and carbon dioxide are exchanged.

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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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📌 Summary:

- Humans inhale oxygen and exhale carbon dioxide.
- Breathing is an involuntary process controlled by the nervous system.
- The respiratory system includes key structures like the nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli, and lungs—each playing a role in moving and exchanging gases.

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