alveolar epithelium

Question 1

The exchange of oxygen and carbon dioxide occurs between

Answer 1

the alveoli and the capillaries in the lungs

Question 2

Oxygen and carbon dioxide are exchanged in a process of

Answer 2

simple diffusion; (passive movement from high to low concentration)

Question 3

The air in the alveoli contains a high concentration of ……….. The oxygen diffuses from the alveoli and into the blood …………, before being carried away to the rest of the body for …………..

Answer 3

oxygen

capillaries

aerobic respiration

Question 4

The blood in the capillaries has a relatively low concentration of …and a high concentration of …………. The carbon dioxide diffuses from the blood and into the ………….and is then exhaled

Answer 4

oxygen

carbon dioxide

alveoli

Question 5

How does a large amount of aveloli affect gas exchange

Answer 5

The large number of alveoli increases the surface area available for oxygen and carbon dioxide to diffuse across

Question 6

The walls of the alveoli are only one cell thick and these cells are flattened
This means that gases have a very

Answer 6

short diffusion distance so gas exchange is quick and efficient

Question 7

The walls of the capillaries are only one cell thick and these cells are flattened, keeping the

Answer 7

diffusion distance short

Question 8

The constant flow of blood through the capillaries means that oxygenated blood is brought away from the alveoli and deoxygenated blood is brought to them
This maintains

Answer 8

high concentration gradient

Question 9

Their walls are moist which helps

Answer 9

The lining of the alveoli walls are also moist so the gases can easily dissolve

Question 10

Surfactant in alveoli is vital for gas exchange as it

Answer 10

lowers surface tension on the surface of alveoli and allows for proper gas exchange during inspiration and expiration