proprioceptor
From ZooTerms (Dictionary of Invertebrate Zoology)
sense organs that lie within the body cavity and respond to internal conditions of the organism.
proprioceptor (noun; Latin proprius, ones own; receptor, receiver): 1. Internal
2. Mechanoreceptors that detect movements or position of the body parts; in arthropods, cordotonal organs, campaniform sensilla, and hair plates.