How many body parts do arachnids have?

Despite the fact that the structure of the body in arachnids is very similar, it differs in different species. In spiders, the body consists of the abdomen and cephalothorax. There is a constriction between them. The body of scorpions is also in two parts, but the abdomen is elongated and has several segments. In ticks, body parts are fused together and represent a whole shell. The body cavity of all arachnids is mixed. Internal organs are located here.