Describe the process of breathing.

Breathing begins with inhalation. This starts with the contraction of the diaphragm, which flattens on contraction pulling the lungs down. The intercostal muscles contract to move the lungs up and out. The contraction of these muscles increases the volume of the lungs, this reduces the air pressure in the lung to below that of the external air. This pressure difference forces air to move in to the lungs where gas exchange occurs. The relaxation of the diaphragm and intercostals reduces the volume of the lungs which therefore increases the air pressure inside the lung to that above the external air. This forces air out of the lungs. The cycle is then repeated. 

Answered by Ava D. Biology tutor

15672 Views

See similar Biology GCSE tutors

Related Biology GCSE answers

All answers ▸

Describe the difference between respiration and breathing.


what is the difference between mitosis and meiosis


What is natural selection?


Describe blood flow through the heart


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences