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.
There are a few candidates for the title of the world's deadliest venomous spider. A 2009 study claims that the Australian âfunnel-webâ spiders (Atrax and Hadronyche) are the spiders most dangerous for humans â their venom causes local and systemic effects, including hypertension, arrhythmia, coma and death.