2.3 Gaseous Exchange

Question 1

In the lungs there is a network of capillaries that surround the alveoli, what happens here?

Answer 1

The diffusion of carbon dioxide and oxygen occurs.

Question 2

Does the blood coming towards the lung have a high or low concentration of carbon dioxide?

Answer 2

High concentration of carbon dioxide.

Question 3

Does the air in the alveoli have a high or low concentration of carbon dioxide?

Answer 3

Low concentration of carbon dioxide.

Question 4

What does having a high concentration of co2 in the blood and a low concentration of co2 in the lungs cause?

Answer 4

A diffusion gradient causing carbon dioxide to move from the blood into the lungs.

Question 5

At the same time of co2 diffusion, what is happening with oxygen?

Answer 5

A high concentration of oxygen within the alveoli from inhaled air and low concentration of oxygen within the blood causes oxygen to diffuse through the thin wall of the alveoli and into the capillary.

Question 6

What does the oxygen bind with in the blood and what is it then called?

Answer 6

Oxygen binds with haemoglobin in the blood to form oxyhaemoglobin.

Question 7

How has the alveoli adapted for gas exchange? (4 reasons)

Answer 7

-They have a large surface area to enable more diffusion of oxygen into the blood from the alveoli, and more co2 out of the blood into the alveoli
-one cell thick so that diffusion distance is small
- lots of blood capillaries to ensure good blood supply to maintain concentration gradients of oxygen and co2.
-have moist surfaces for gases to dissolve in to form a solution to pass through the cell membrane

Question 8

What does diffusion mean?

Answer 8

The word used to describe the movement of gases.

Question 9

What does diffusion gradient mean?

Answer 9

Diffusion gradient means the rate of the movement of gases.