Essay On Ventilation And Exhalation

Introduction

Ventilation is a process which consists of two parts: inhalation and exhalation. Inhalation is the movement of air into the lungs, while exhalation is the movement of air out of the lungs. During this process, the diaphragm shrinks and the intercostal muscles move the ribs upwards, which increases the area and decreases the pressure. When the diaphragm and the intercostal muscles rest, the area decreases and the pressure increases pushing the air out. Hence, different body positions, such as bending down while sitting, can reduce the lung capacity, thus, the rate of respiration, as the empty space in the lungs is reduced. Ventilation is significant to humans in order to balance gases in the alveoli and to carry out cell respiration.

A 2006 report by the American Academy of Physical Medicine, carried out by using 70 wheel-chaired participants, found that change in body positioning posture causes a change in respiratory function, hence, lung capacity. (Martin, A, 2014) Moreover, according to the researchers in the Department of Medicine of Duke University School of Medicine, in the standing position, the lung capacity was significantly larger than in the sitting position, while it became even smaller when the subject lay down. (Blair, E, Hickam, JB, 1954)

I have realised that some positions are harder to breathe in, thus I assumed that different body positions can affect my lung capacity. This is why I decided to investigate the effect of different body positions on lung capacity. The forced vital capacity (FVC) is a pulmonary function measure often used for this purpose and is defined as the maximum volume of air exhaled from after maximum inspiration (Martinez, BP, et al, 2015), which was the measure used in this