Question

During exhalation, the ribs ________.

• A. Move outwards
• B. Move downwards
• C. Move upwards
• D. Do not move at all

Answer 1

The correct option is B Move downwards

• Exhalation is the flow of the breath out of an organism. In humans, it is the movement of air from the lungs out of the airways, to the external environment during breathing.
• During exhalation, the diaphragm relaxes and moves upward into the chest cavity. The intercostal muscles between the ribs also relax to reduce the space in the chest cavity. As they relax they position the rib cage downwards and inwards.
  
• As the space in the chest cavity gets smaller, the air rich in Carbon dioxide is forced out of the lungs and windpipe and then out of the nose or mouth.
• Hence, during exhalation, the ribs move downwards.

So, the correct answer is option B.