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.
In general, all spiders bite, but their bites are not all equally poisonous. Most spider bites are no worse than a mosquito bite. However the black widow and the brown recluse bites are quite poisonous.They eat insects, which leads many people to believe they are a good thing to have around. Spiders are of the family arachnid.They have two body parts, eight segmented legs and fangs that inject venom into their victims. They have no antennae.owever the black widow and the brown recluse bites are quite poisonous. They eat insects, which leads many people to believe they are a good thing to have around. Spiders are of the family arachnid. They have two body parts, eight segmented legs and fangs that inject venom into their victims. They have no antennae.