Answers

2014-06-16T19:01:44+08:00
When we breath in, the diaphragm contracts and flattens, the chest cavity enlarges and so air goes in. When the diaphragm relaxes, air is forced out of the lungs :)
1 5 1
2014-06-16T19:02:42+08:00
The diaphragm helps to push the air out by deflating, and it helps the oxygen go in by inflating.
1 5 1