Nerve injuries are classified as follows: 1  A first-degree injury, or neurapraxia, will recover within days after the injury, or it may take up to three months.  A second-degree injury, or axonotmesis, also will recover completely; however, the recovery will take much longer than with a first-degree injury.
Freebase(0.00 / 0 votes)Rate this definition: Churning. Churning is the process of shaking up cream to make butter, and various forms of butter churn have been used for the purpose. In Europe from the Middle Ages until the Industrial Revolution, this was generally as simple as a barrel with a plunger in it, which was moved by hand.
A riffle is an area of fast moving, churning water. A run is an area of smoothly moving water. A pool is an area of stagnant water. Each habitat type supports different types of aquatic life, so a stream with a greater diversity of habitat types will generally support a greater diversity of organisms.