part_of adult capitulum adult body adult peripheral sensillum adult seta A hair like process that extends from the cuticle to the exterior. The seta is the most common type of sensillum. The seta isinserted into a socket, a depression in the cuticle surrounded by a slight ridge. The interior of the seta is hollow and connected directly to a duct that extends through the cuticle to the epidermis. Several neurons embedded in the epidermis innervate the setiform sensillum, sending dendrites into the shaft of the seta. Axons from the neuron cell bodies extend into the interior of the body and communicate via nerves to the synganglion. Most setae are simple, without pores and serve as mechanosensilla and are innervated by mechanosensory neurons. Specialized setae have either single pores at the tip (gustatory sensilla), pores all over the sensilla (olfactosensilla) or pores in ridges along the side walls or with grooves that lack pores. These latter sensilla are believed to function as hygrosensilla or thermosensilla or both. Fig. 5-1, Fig. 5-10, in Biology of Ticks ISBN:0-19-505910-7. TADS:0000301 TADS:0000301 default_namespace adult sensory system