2- Inhaling and Exhaling

Question 1

what happens when we inhale?

Answer 1

the intercostal muscles between the ribs contract and pull the ribs upward. at the same time the diaphragm contracts and flattens. this means that there is now more space inside the chest so air is drawn into the lungs

Question 2

what happens when we exhale?

Answer 2

the muscles between the ribs relax and the ribs move downwards. the diaphragm also relaxes and moves upwards. this means there is less space inside the chest so air is forced out of the lungs.

Question 3

mechanism of inhaling

Answer 3

1- the intercostal muscles contract and pull the ribs up and out
2- the diaphragm contracts and flattens
3- the volume in the thorax increases
4- the pressure in the
thorax decreases
5- air rushes in from an area of higher pressure outside to an area of lower pressure inside

Question 4

mechanism of exhaling

Answer 4

1- the intercostal muscles relax and the ribs move down
2- the diaphragm relaxes and returns to a dome shape
3- the volume in the thorax decreases
4- the pressure in the thorax increases
5- air is forced out from an area of higher pressure inside an area of lower pressure outside