  In traditional engines (not overhead cam), the camshaft pushes lifters UP. Lifters push the pushrods UP, but the valves need to be pushed DOWN... so the rocker arm rock â¦ s on a shaft that pushes one side down when the other side goes up. It's not a difficult job.Rocker arms aren't doing the most stressful job in the engine, but they do eventually wear out.ifters push the pushrods UP, but the valves need to be pushed DOWN... so the rocker arm rock â¦ s on a shaft that pushes one side down when the other side goes up. It's not a difficult job. Rocker arms aren't doing the most stressful job in the engine, but they do eventually wear out.
1 These nerve cells are found in a tiny patch of tissue high up in the nose, and they connect directly to the brain.  Gustatory (taste nerve) cells are clustered in the taste buds of the mouth and throat. They react to food or drink mixed with saliva. Many of the small bumps that can be seen on the tongue contain taste buds. These surface cells send taste information to nearby nerve fibers, which send messages to the brain.
Smell, the nose, and the brain. Molecules of the food you are eating move through the back of the throat and reach olfactory nerve endings in the roof of the nose. The molecules bind to these nerve endings, which then signal the olfactory bulb to send smell messages to two critical parts of the brain:f course, we have to know what we are eating, so taste, smell, and trigeminal messages meet in a part of the brain called the insula (not shown in the image above), which identifies what the flavor is.