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.
Grass Spiders are not harmful to humans. They are actually creatures which helps keep the delicate balance of nature wherever they reside. As such, their presence is a sign of a healthy ecosystem and is thus beneficial to humans.owever, Grass Spiders or Funnel Weavers are easy to distinguish from Wolf Spiders because Wolfs do not construct webs but rather hunts for prey actively. The Spider is also known as Funnel Weaver Spider because of the shape of their webs.