Robert #Boyle is known for being one of the pioneers in experimentation in the field of #chemistry and a precursor of the modern theory of the chemical elements. However, his scientific contributions extend to biological sciences, especially to the #physiology of #breathing.

Boyle’s law is a particular gas law called after this English scientist, who first announced it in 1662. This gas law describes the relationship between the pressure and volume of gas for a mass and temperature, and partly explain the mechanism by which the human respiratory system functions. Boyle’s law is equivalent to PV = K (P is pressure, V is volume, K is a constant), or one may state that pressure is inversely proportional to the volume.

The human body brings air into the #lungs by negative pressure. At baseline, the thoracic cavity is in static equilibrium with an #intrapleural pressure near -5 cm H2O. During #inspiration, there is a contraction of inspiratory muscles (namely, the diaphragm and external intercostal muscles [additional muscles, such as the scalene and sternocleidomastoid, can take part under specific circumstances]) that increases #intrathoracic volume. Due to the combined motion of the lungs and the chest wall, the lungs begin to expand as the thorax expands during inspiration. According to Boyle’s law, as the volume increases, the pressure must decrease; therefore, as the intrapleural volume increases, the intrapleural pressure decreases to about -8 cm H2O at end inspiration.

When the inspiratory muscles relax, the volume within the thorax decreases; thus, the pressure increases and forces out alveolar air back into the atmosphere. With inspiration, lung volume increases and intrapleural pressure decreases; with #expiration, lung volume decreases and intrapleural pressure increases.

Boyle was also a great visionary and if he could raise his head he would be delighted with the society he would find himself in, because many of the things he predicted have come true. These include, for example, the possibility of organ transplants, the use of devices that can provide us with information about geographic longitude, increased life expectancy, the ability to wear new teeth, change the colour of grey hair, the availability of powerful analgesics that can alleviate pain, as well as narcotics that induce dreams or drugs that stimulate the imagination.

📸 Breathing occurs because expanding and contracting lung volume creates small pressure differences between the lungs and surroundings (according to Boyle's law), causing air to be drawn into and forced out of the lungs.
#Boyle #chemistry #physiology #breathing