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.
Using these words and information we can now summarise osmosis with its definition. Osmosis is the movement of water molecules through a selectively permeable membrane from higher water concentration to a lower water concentration-or-down a concentration gradient. Animal cells are surrounded only by the membrane and may swell up and burst if too much water enters by osmosis.