Parts of the Respiratory System Worksheet worksheet - Free Printable

Let’s work through this step by step.

We are looking at a diagram of the human respiratory system with labels A to F.

First, let’s identify what each label likely represents based on standard anatomy:

- A is pointing to the nasal cavity or upper part of the throat — where air enters. Cilia are found here to trap dust and germs.
- B is pointing to the larynx (voice box) — located just below the pharynx.
- C is pointing to the trachea (windpipe) — the tube that carries air down to the lungs.
- D is pointing to the bronchi — branches from the trachea into the lungs.
- E is pointing to alveoli — tiny air sacs in the lungs where gas exchange happens.
- F is pointing to the diaphragm — the muscle below the lungs that helps with breathing.

Now, let’s answer each question:

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a. Label the parts marked B and C.

- B = Larynx (or voice box)
- C = Trachea (or windpipe)

These are standard terms used in biology for these structures.

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b. (i) Give the function of the cilia found in the part labelled A.

Cilia are tiny hair-like structures. In the nasal cavity (A), they help trap dust, pollen, and germs from the air we breathe. They also move mucus (which traps particles) toward the throat so it can be swallowed or spit out. This keeps our lungs clean.

So, function: *To trap dust and germs and move them away from the lungs.*

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(ii) Name ONE other labelled part which contains similar structures.

Cilia are also found in the trachea (C) and bronchi (D). So either C or D would be correct.

Let’s pick C (trachea) — it’s clearly labeled and has ciliated lining.

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(iii) What is the effect of cigarette smoke on these structures?

Cigarette smoke damages or paralyzes the cilia. When cilia don’t work, mucus and dirt build up in the airways. This can cause coughing, infections, and long-term damage like bronchitis or even cancer.

Simple answer: *It damages or stops the cilia from working.*

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c. State the effect cancer of the throat area will have on the part labelled B.

Part B is the larynx (voice box). If there’s cancer in the throat area near the larynx, it can grow into or press on the larynx. This might make it hard to speak, swallow, or breathe. It could also require surgery that removes part or all of the larynx, leading to loss of voice.

Simple answer: *It may damage or block the larynx, affecting speech or breathing.*

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Final Answer:

a. B: Larynx; C: Trachea
b. (i) To trap dust and germs and move them out of the airway
(ii) C (or D)
(iii) It damages or paralyzes the cilia
c. It may damage or block the larynx, affecting speech or breathing