Describe the structure and function of nerves. What is a "mixed nerve?"
Neuronal fibers (axons and dendrites) joined together by connective tissue form compound structures called nerves. Within a nerve, each neuronal fiber conducts its impulses separately, insulated from all others by its glial cell sheath. Nerves, thus, consist of up to thousands of completely separate impulse pathways which are bound together for structural convenience. Some nerves contain only sensor neurons, some only effector neurons, and some both types at the same time. In the lattermost case, the nerves are known as mixed nerves.
