The Mechanical Process of Breathing


TheMechanical Process of Breathing

Breathingis a mechanical method, whereby fresh air consisting of more oxygenis sucked into the lungs while waste air full of carbon dioxide ispumped out (Baker, 2016). Breathing is considered to be a mechanicalprocess in most vertebrates that involves two phases, inspiration,and expiration. People require a constant oxygen supply for cellularrespiration. They also need to defecate carbon dioxide, a poisonousgas, which is the waste product of this process. Therefore, duringinspiration, fresh air that is rich in oxygen is transported to thelungs (Baker, 2016). During this time the space inside the chestcavity is augmented as the intercostal muscles and diaphragmcontract. Hence, the diaphragm makes a downward movement resulting inthe chest cavity increasing in volume while the intercostal musclespull the ribs upwards causing the rib cage to expand leading to thevolume to enhance further (Baker, 2016). The volume increase resultsin the reduction of air pressure in the alveoli. Therefore, since airusually moves from a high-pressure region to a low one, it flowsquickly through the respiratory tract to the alveoli leading tonegative pressure breathing.

Conversely,during expiration the intercostal muscles and diaphragm often relax.As such, the thoracic cavity returns to its former volume, enhancingthe lungs’ air pressure. Thus, air is forced out of the lungs. Airin the lungs, usually rushes out because of the pressure gradientbetween the atmosphere and thoracic cavity (Baker, 2016). Hence, thecorrelations between gas volume and pressure as explained by Boyle’slaw helps to elaborate the mechanics of breathing. As the law states,in a sealed space volume and pressure, have an inverse relation.Therefore, when the pressure increases, volume decreases and viceversa as shown in the breathing process.


Baker,D. J. (2016). Artificialventilation: A basic clinical guide.Switzerland: Springer.