B6.6-8 Human Gas Exchange

Question 1

Order in the human gas exchange system

Answer 1

Lungs
Trachea
Bronchi
Bronchioles
Alveoli

Question 2

Process of inspiration (inhalation)

Answer 2

Diaphragm contracts
External intercostal muscles contract
(Internal intercostal muscles relax)
Decreased pressure increased volume
Air is forced into lungs

Question 3

Process of expiration (exhalation)

Answer 3

Diaphragm relaxes
Internal intercostal muscles contract
(External intercostal muscles relax)
Increased pressure decreased volume
Air is forced out of lungs

Question 4

3 ways that the alveoli maximise rate of diffusion

Answer 4

Short diffusion pathway
large surface area
Steep concentration gradients

Question 5

The _ _ is only 1 cell thick

Answer 5

Alveolar epithelium