Each question is worth 2 marks.
Each point you make is worth 0.5 mark.
You should describe four different things to get full marks.
Write your answers as sentences.
Use the essence of the question as the start of your answer.

Explain the significance of the structure to the function of the following.

1. Cartilage rings in the trachea.

2. Cilia of the epithelial layer of the respiratory tract.

3. Membranes of the nasal cavity.

4. Shape and tension of the vocal chords.

5. Pleural fluid and membranes.

Each different valid point you make is worth 0.5 mark.
Write your answers as sentences.
Use the essence of the question as the start of your answer.

Write answers to the following questions.

1. How does the contraction of the diaphragm affect the volume of the thorax? (1 mark)

2. How does the relaxation of the intercostal muscles affect air pressure in the lungs? (2 marks)

3. Why must the thorax be airtight? (2 marks)

Give the most suitable human biology term for each of the following.

1. The cavity at the back of the mouth which is a common passageway for both food and air.

2. The voice box.

3. The wind pipe.

4. “Grape-like” pouches in the air sacs of the lung through which gas exchange takes place.

5. The difference in concentration of a substance between two places.
That substance will attempt to diffuse from the area of its higher concentration to the area of its lower concentration.

6. The chemical found in red blood cells which binds onto and releases oxygen.

7. The amount of a substance (that is, the number of molecules) per unit volume.

8. The small flap of tissue which hangs from the soft palate and prevents food from entering the nasal cavity while swallowing.

9. A covering of the opening of the windpipe.

10. The double membrane which covers the lungs.