Ventilation

Question 1

what is ventilation?

Answer 1

• the process of moving air into and out of the lungs (inhalation and exhalation)
• moving air relies on differences in air pressure between the lungs and the atmosphere

Question 2

process of inhalation

Answer 2

1. diaphragm contracts, moving down and flattening
2. intercostal muscles contract, moving rib cage up and out
3. volume of thorax increases
4. air pressures in the thorax falls
5. air pressure in the thorax is now less than atmospheric pressure, causing air to move into the lungs

Question 3

process of exhalation

Answer 3

1. diaphragm relaxes, moving up and doming
2. intercostal muscles relax, moving rib cage down and in
3. the volume of the thorax decreases
4. air pressure in the thorax rises
5. air pressure in the thorax is now more than atmospheric pressure, causing air to move out of the lungs