Respiratory system online activity for Grade 8 - Free Printable

Let's solve the worksheet step by step.

---

1. Write the parts of the respiratory system

We need to label the numbered parts in the diagram of the human respiratory system.

Here is the correct labeling based on standard anatomy:

- 1 → Nose
- 2 → Nasal cavity
- 3 → Larynx (voice box)
- 4 → Trachea (windpipe)
- 5 → Right lung
- 6 → Bronchi
- 7 → Alveoli (air sacs)
- 8 → Diaphragm

> ✔ Explanation:
The respiratory system starts at the nose and mouth, where air enters. It passes through the nasal cavity, then down the pharynx and larynx into the trachea. The trachea splits into bronchi that enter the lungs. Inside the lungs, the bronchi branch into smaller tubes ending in alveoli, where gas exchange occurs. The diaphragm is a muscle below the lungs that helps with breathing.

---

2. Complete the text about the process of respiration

Use the words provided:
*Breath out, Breathe in, blood, trachea, air, nose, bronchi, Carbon dioxide, lungs, oxygen, nostrils*

Now fill in the blanks logically:

> First, air enters through our nostrils and nose.
> The air goes down through the trachea and the bronchi.
> The lungs enters in the air.
> Oxygen (O₂) passes into the blood.
> Carbon dioxide (CO₂) leaves our body when we breathe out.

✔ Final completed text:

> First, air enters through our nostrils and nose.
> The air goes down through the trachea and the bronchi.
> The lungs enters in the air.
> Oxygen (O₂) passes into the blood.
> Carbon dioxide (CO₂) leaves our body when we breathe out.

> 🔍 Note: There's a slight grammatical issue in the third sentence — it should be "The air enters the lungs" rather than "The lungs enters in the air." But since this is likely a student exercise, we follow the given structure as best as possible.

---

✔ Final Answer Summary:

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

#### Part 2 – Completed Text:
First, air enters through our nostrils and nose.
The air goes down through the trachea and the bronchi.
The lungs enters in the air.
Oxygen (O₂) passes into the blood.
Carbon dioxide (CO₂) leaves our body when we breathe out.

Let me know if you'd like a printable version or explanation for younger students!