2.2: Adaptations for gas exchange in humans

Question 1

The alveolus are covered by?

Answer 1

an extensive capillary network.

Question 2

How does the human respiratory system maintain a high concentration gradient?

Answer 2

Oxygenated blood is carried away whilst carbonated blood is taken to.

Question 3

What is the first step of breathing in?

Answer 3

Intercostal muscles contract, ribs move up and out.

Question 4

What is the second step of breathing in?

Answer 4

Diaphragm contacts and flattens.

Question 5

What is the third step of breathing in?

Answer 5

Volume of chest cavity increases, pressure is lowered.

Question 6

What is the fourth step of breathing in?

Answer 6

Air is drawn in.

Question 7

What is the first step of breathing out?

Answer 7

Intercostal muscles relax, ribs move down and in.

Question 8

What is the second step of breathing out?

Answer 8

The diaphragm relaxes and expands.

Question 9

What is the third step of breathing out?

Answer 9

Volume of chest cavity decreases and pressure is raised.

Question 10

What is the fourth step of breathing out?

Answer 10

Air is pushed out.