Question

KEY QUESTIONS Lesson 14: Respiratory System List the structures that a molecule of oxygen gas passes through, as it enters 7. Why is the nose the preferred entry-way of air (as opposed to the mouth)? i2 8. What is the H1N1 virus? What happens when someone has contracted the 6. the nose and finishes at a red blood cell. 16 marks) marks) virus (identify symptoms)? Describe normal respiratory function and compare it to the respiratory function during infection with the virus. What can someone do to prevent contraction and the spread of the H1N1 virus? (10 marks) 9. Research 2 effects that smoking has on the respiratory system. (2 mark

Answer 1

Ans 6-

1. Air containing oxygen first enters through nose.

2. Then passes through cilia present on the wall of nose and wind pipe.

3. From wind pipe it enters trachea.

4. From trachea small pipes called bronchii originates and oxygen in the air passes through it.

5. Bronchii further divides into bronchioles inside the lungs and air containing oxygen enters them.

6. Bronchioles opens into balloon like structures known as alveoli (basal unit of lungs) which is richly supplied with blood vessels.

7. When air reaches alveoli oxygen passes through alveolar membranes into the blood.

8. Blood contains RBCs which binds this oxygen in their haemoglobin and then transports it to the different parts of body.

Ans 7- Preferred organ for respiration is nose because nose contains small hair like structures known as cilia which prevents dust, mites and harmful microbes from entering into the trachea.

If air is inhaled from mouth these microbes can easily enter into trachea due to absence of cilia and then they can cause respiratory tract infections.