👉 Pre-fluid, also known as the pre-respiratory phase or pre-ventilation phase, is a critical period in the respiratory cycle that occurs before the actual inhalation of air. During this phase, the diaphragm and intercostal muscles relax, causing the chest cavity to decrease in volume. This reduction in volume leads to an increase in intra-thoracic pressure, which eventually forces air out of the lungs through the respiratory tract. Essentially, the pre-fluid phase is a preparatory stage where the body readies itself for inhalation by creating the necessary pressure gradient for air to exit the lungs.
