Process of Breathing :
- The mechanism by which organisms obtain oxygen from the environment and release Carbondioxide, is termed as Breathing.
- -- In human beings, air is taken through the nostrils. The entire nasal passage is lined with mucus which help in the filtration of air . From nostrils, the air pases through the throat and ultimately into the lungs.
- Rings of cartilage are present in the throat which ensure that the air passage does not collapse.
- within the lungs , the bronchi divides into bronchioles and bronchioles called alveoli which provide larger surface where exchange of gases can take place.
- The walls of alveoli contain an extensive network of blood vessels which help in easier transportation of gases to all the cells in the body.
- During breathing ribs gets raised which flatten the diaphragm resulting in larger chest cavity . Due to this , air is sųcked into the lungs and fills the expanded alveoli ( Inhalation ).
- During the breathing cycle , when air is taken in and let out ( exhalation ) , the lungs always contain a residual volume of air so that there is sufficient time for oxygen to be absorbed and for the Carbondioxide to be released.
[ Diagram - refer to attachment ]