G7 - Introduction to the respiratory system

What is the main purpose of the respiratory system?

• To digest food and absorb nutrients.

• To circulate blood throughout the body.

• To extract oxygen from the air and remove carbon dioxide.

• To filter waste products from the blood.

Which sequence correctly describes the path an oxygen molecule takes when inhaled?

• Mouth/Nose -> Bronchioles -> Trachea -> Bronchus -> Alveolus

• Mouth/Nose -> Trachea -> Bronchus -> Bronchioles -> Alveolus

• Mouth/Nose -> Alveolus -> Bronchus -> Trachea -> Bronchioles

• Mouth/Nose -> Bronchus -> Trachea -> Bronchioles -> Alveolus

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How does oxygen move from the alveoli into the bloodstream?

• Active transport

• Osmosis

• Diffusion

• Filtration

What are the tiny hair-like structures in the trachea and bronchi that help remove trapped particles?

• Alveoli

• Capillaries

• Cilia

• Goblet cells