end organ

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The encapsulated termination of a sensory nerve.

from The Century Dictionary.

• noun In physiology, any specialized structure which forms the terminus of a path of nervous conduction: usually applied to the terminal organs at the periphery of the body.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a specialized structure at the peripheral end of some motor or sensory nerve fibers