Final answer:
The difference between positive pressure and negative pressure breathing lies in whether the air pressure in the lungs is higher or lower than atmospheric pressure during breathing. Negative pressure occurs during inhalation and positive pressure during exhalation, with these mechanisms being vital for pulmonary ventilation and gas exchange.
Step-by-step explanation:
Difference Between Positive Pressure Breathing and Negative Pressure Breathing
Positive pressure breathing and negative pressure breathing relate to the pressures exerted in the lungs during the process of inhalation and exhalation. Negative pressure breathing involves a pressure lower than the atmospheric pressure and occurs when we inhale.
The diaphragm and chest muscles contract, increasing the volume of the thoracic cavity, thus reducing the pressure inside the lungs resulting in air being drawn into the alveoli.
In contrast, positive pressure breathing is when the pressure inside the lungs rises above atmospheric pressure during exhalation. This is achieved by the diaphragm and chest muscles relaxing, decreasing the thoracic cavity's volume and forcing air out of the lungs.
These breathing mechanisms are crucial for the exchange of gases (oxygen and carbon dioxide) between our body and the environment, regulated to maintain blood gas homeostasis and pH balance.
The pressure gradient created by these pressure changes enables the movement of gases in and out of the lungs, adhering to the basic principle that air flows from an area of higher pressure to an area of lower pressure.
Pulmonary ventilation is the term used for the process of breathing, which is essential to life as it facilitates the uptake of oxygen required for cellular metabolism and the removal of carbon dioxide, a byproduct of this metabolic process.