In this Article. In this Article. A solitary pulmonary nodule (SPN) is a single abnormality in the lung that is smaller than 3 cm in diameter. Generally, a pulmonary nodule must grow to at least 1 cm in diameter before it can be seen on a chest X-ray.
Osmosis is the scientific process of transferring fluid between molecules. When molecules move in and out of a cell to achieve the same concentration of something, like salt, on both sides, then osmosis is happening.
Osmosis is a special type of diffusion whereby water is moved from an area of high water potential into an area of lower water potential. In principle, the same concepts applyâ¦ for osmosis as it does for diffusion. The particles travel in a concentration gradient without the use of energy.