"In effect, the motile cilium is a nanomachine composed of perhaps over 600 proteins in molecular complexes, many of which also function independently as nanomachines." Cilia "function as mechano- or chemosensors and as a cellular global positioning system to detect changes in the surrounding environment." For example, ciliary signaling plays a role in the initiation of cellular replacement after cell damage. In addition to this sensory role mediating specific signaling cues, cilia play "a secretory role in which a soluble protein is released to have an effect downstream of the fluid flow" in epithelial cells, and can of course mediate fluid flow directly in the case of motile cilia. Primary cilia in the retina play a role in transferring nourishment to the non-vascularized rod and cone cells from the vascularized cells several micrometres behind the surface of the retina. Signal transduction pathways involved include the Hedgehog signaling pathway and the Wnt signaling pathway. Dysfunctional cilia can lead to: * Chemosensation abnormalities, typically via ciliated epithelial cellular dysfunction. * Defective thermosensation or mechanosensation, often via ciliated epithelial cellular dysfunction. * Cellular motility dysfunction * Issues with displacement of extracellular fluid * Paracrine signal transduction abnormalities In organisms of normal health, cilia are critical for: * development * homeostasis * reproduction
Ciliopathy
Chondropathy
Enthesopathy
Spondylopathy
Osteosclerosis
Poliosis
Osteopathy
Pediculosis