gas exchange system

Question 1

Where are the lungs found in the body?

Answer 1

The lungs are located in the thorax (within the chest). They are protected by the ribcage and separated from the rest of the abdomen by the diaphragm.

Question 2

What tissues and organs make up the gas exchange system?

Answer 2

● Trachea
● Intercostal muscles
● Bronchi
● Bronchioles
● Alveoli
● Diaphragm

Question 3

Explain how the lungs are ventilated by the action of intercostal muscles

Answer 3

● Intercostal muscles contract
● Ribcage moves upwards and outwards
● Diaphragm flattens and volume of the chest increases
● Increased volume results in decreased pressure
● Air is drawn into lungs down pressure gradient

The inverse occurs when air moves out of the lungs.

Question 4

Describe how gas exchange occurs at the alveoli

Answer 4

● Oxygen diffuses from the alveoli into the capillary bloodstream down its concentration gradient.
● Carbon dioxide diffuses from the capillary into
the alveoli down its concentration gradient.

Question 5

Describe how alveoli are adapted for gas exchange

Answer 5

● Small and arranged in clusters - larger surface area.
● Rich blood supply - maintains concentration gradient.
● Thin alveolar wall - short diffusion pathway.

Question 6

How would you calculate the breathing rate

Answer 6

Number of breaths / number of minutes