Question

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

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

Answer 1

• During inspiration, the ribs move upwards and outwards due to the contraction of the external intercostal muscles.
• The internal intercostal muscles remain relaxed.
• The muscular dome-shaped diaphragm contracts and flattens.
• These movements allow the increase in the volume of chest cavity, thereby facilitating the entry of the air rich in oxygen.