Medical Definition of ARTHRODESIS. : the surgical immobilization of a joint so that the bones grow solidly together: artificial ankylosis. the surgical immobilization of a joint so that the bones grow solidly together. ADVERTISEMENT.
Trapdoor spiders are not particularly harmful to man however, like Tarantulas, the tiny hairs on the legs of some species leave tiny red marks where the toothed hairs on the spiders' feet have clung to the skin. Mouse spiders are also a type of Trapdoor spider with huge chelicerae and may measure up to 35mm in body length.
Spiders are both harmful and helpful to humans. Later in this article we take a look at the threat spiders pose to humans. First we take a look at the good things spiders do for us.Spiders reduce local disease carrying insects that would other wise be harmful to us humans.Eliminating these threats is of great benefit to our safety and health. Spiders provide humans with many other benefits one very significant being that of medical advances. Spider venom is used in neurological research.piders reduce local disease carrying insects that would other wise be harmful to us humans. Eliminating these threats is of great benefit to our safety and health. Spiders provide humans with many other benefits one very significant being that of medical advances.