2023.03.29_F3 Revision Chapter 2

Why the concentration of oxygen becomes high in the blood capillaries on the alveolus?

• Oxygen diffuses into alveolus

• Oxygen diffuses into the blood capillaries

• Carbon dioxide diffuses into the blood capillaries

• Carbon dioxide diffuses into the red blood cells

The diagram below shows a part of the human lungs. Which of the following shows the characteristics of the part?

I The blood capillaries have thick walls

II Moist surface

III Surrounded by a network of blood capillaries

IV Small surface area of alveolus

• I and II

• I and III

• II and III

• III and IV

Diagram shows the flow of blood in a blood capillary on the alveolar wall. Which part A, B, C or D has the highest oxygen concentration?

• A

• B

• C

• D

The process of gaseous exchange that occurs on the surfaces of the lungs is called

• diffusion

• photosynthesis

• transpiration

• osmosis

Which characteristics facilitates respiratory gases to dissolve and diffuse across the walls of the alveoli?

• Moist and thin

• A large surface area

• A very large number of alveoli

• Covered with a compact network of blood capillaries

Which of the following conditions help increase the efficiency of gaseous exchange between the alveoli and blood capillaries?

• Thin alveolar walls and

  A few blood capillaries

• Thick alveolar walls and

  many blood capillaries

• Thin alveolar walls and

  many blood capillaries

• Thick alveolar walls and

  a few blood capillaries