principles that relate to efficient gas exchange

Question 1

Why is it important for alveoli and capillaries to be close together

Answer 1

Because the walls of the alveoli share a membrane with the capillaries

This lets oxygen and carbon dioxide diffuse, or move freely, between the respiratory system and the bloodstream.

Question 2

Why are the capillaries one cell thick

Answer 2

so there is a short diffusion pathway for diffusion to take place

so there is a faster rate of diffusion of oxygen from alveoli into the blood.

Question 3

why does the alveoli have a large surface area?

Answer 3

to process the huge amount of air involved in breathing and getting the oxygen into the lungs and bloodstream.

Question 4

What is the diffusion gradient in the lungs?

Answer 4

breathing ensures that the oxygen concentration in the alveoli is higher than in the capillaries so oxygen moves from the alveoli to the blood.

Question 5

for oxygen where is the high concentration and where does oxygen diffuse

Answer 5

oxygen diffuses from a high concentration inside the alveoli down a concentration gradient to an area of lower concentration to the blood capillary.

Question 6

for carbon dioxide where is the high concentration and where does it diffuse

Answer 6

Carbon dioxide diffuses from a high concentration inside the blood capillary down a concentration gradient to an area of lower concentration in the alveoli.