2.1

Question 1

What is the process of breathing?

Answer 1

Inhaling and exhaling air by the lungs

Question 2

How does the breathing mechanism work for inhalation?

Answer 2

1.The intercostal muscle contracts and the rib cage moves upward
2. The diaphragm muscle contract and **flatten*
3. the air pressure in the thoracic cavity decreases
4.The higher air pressure outside forces air to enter the lungs

Question 3

How does the breathing mechanism work for exhalation?

Answer 3

1. the intercostal muscle relax and the rib cage moves downward and inwards
   2.The diaphragm muscle relax and curve upwards.
   3.the air pressure in the thoracic cavity increases
   4.The high air pressure in the lungs pushes air out