Question

what does negative and positive pressure breathing mean ?

Answer 1

Breathing involves two process- inspiration and expiration. Both the process takes place because of the difference in the pressure gradient. When the atmospheric pressure is higher than the pressure inside the lungs it is known as negative pressure and results in the inhalation. Similarly, when the pressure inside the lungs is higher than the outside atmospheric pressure , it is known as positive pressure and results in the exhalation.