gas exchange

Question 1

what are the three adaptations of leaf tissue for gas exchange for gas exchange

Answer 1

1. stomata allow diffusion of gases in and out of the plant
2. thin to shorten to diffusion distance
3. air spaces in the spongy mesophyll layer allow cases to diffuse

Question 2

the general structure of the lungs

Answer 2

1. trachea branches into two bronchi
2. bronchi branch into bronchioles
3. bronchioles terminate in alveoli

Question 3

the structure of an alveolus

Answer 3

• small sacs with capillaries around them
• contain a surfactant so walls don’t stick together and so gases can dissolve to help diffusion

Question 4

what is the purpose of the pleural membrane

Answer 4

the pleural membrane covers the lung, reduces friction and keeps the lungs moist

Question 5

what are intercostal muscles

Answer 5

they are a group of muscles found between the ribs that involves in breathing by changing the size of the thorax

Question 6

how does smokers cough arise

Answer 6

• cilia on cells lining the trachea waft mucus containing dirt out of the lungs
• smoking can kills lining the trachea
• a build up of mucus in the lungs can cause people to develop smokers cough