👉 The "stops fluid" refers to the smooth and continuous movement of air through the respiratory system, which is essential for effective gas exchange in the lungs. This fluid, primarily composed of water and various dissolved substances, acts as a lubricant that prevents the collapse of the alveoli (tiny air sacs in the lungs) during exhalation. When the diaphragm and intercostal muscles contract, they create negative pressure in the thoracic cavity, drawing air into the lungs. As exhalation occurs, the muscles relax, and the elastic recoil of the lung tissue and the surface tension within the alveoli help expel air. The fluid ensures that these processes occur without obstruction, maintaining an efficient flow of air and facilitating the exchange of oxygen and carbon dioxide between the lungs and the bloodstream.
