Question

With regard to the respiratory system and the process of respiration in man, answer the following question:

Briefly describe how the above mentioned muscles help in the inspiration of air. 

Answer 1

(i) The ribs are moved inwards and outwards by the intercostal muscles stretched between them and thereby, enlarges the chest cavity.

(ii) The diaphragm flattens and presses the organs inside the abdomen. When the abdominal muscles relax, the abdominal wall moves outwards.