Question

During exhalation, what happens to the ribs?
(A) Move outwards
(B) Move downwards
(C) Move upwards
(D) Do not move at all

Answer 1

Hint: Respiration is the process that takes place in two phases namely inhalation or breathe in and exhalation or breathe out. During this, oxygen is inhaled reaches the lungs and the gaseous exchange takes place in alveoli and the carbodiimide is released

Complete answer: or Complete step by step answer:
Exhalation is the process of exhaling or breathing out of the inhaled air. It is the passive process where inhaling is the active process. During the process of exhalation, the air from the lungs moves out to the external atmosphere.

During the time of inhalation, the air from the external environment moves into the lungs through the nose and tracheal cavity. At this time, the chest region enlarges due to the filling of air in the chest and diaphragm moves downward and the ribs move outwards and upwards. But at the time of exhalation, the air in the intercostal space is forced out to the nose and to the external environment, so the diaphragm and the intercostal muscle between the ribs get relaxed and hence the diaphragm moves upward whereas the ribs move downward and inward.

Thus, the option (B) is correct.

Note:
All organisms involve respiration this is because oxygen is important to break down the complex molecules in the food into simpler molecules in order to release energy. Alveoli is responsible for the gaseous exchange; it transfers the oxygen from the lungs to the blood vessels.