Spider has two distinct body parts. The first consists of a fused head and breast called as cephalothorax. It is made from a hardened material, called chitin. The second, rear part is the soft abdomen, called opisthosoma. A tiny tube called pedicel connects the cephalothorax and abdomen.
The eight legs, the two jaws (chelicerae) and the two feelers (palps) are connected to the cephalothorax. The males have a bulb at the end of their palps. These are filled with semen before copulation and are used to inject the semen into the sexual organs of the female.
The brains are located in the cephalothorax and the heart at the front upper side of the abdomen. The back or top of a spider is the dorsal side and at the bottom is called the ventral side. The genitals of the spider (epigynum) are located just behind the legs on the ventral side. The silk making spinners (white) are located at the rear of the abdomen. The book lung/trachea are enclosed in theabdomenJaws and fangs
Primitive spiders, Mygalomorphae, have forwardly pointing jaws that move forwards and backward in contrast to the modern spider. Therefore they can not crunch a prey. They wait until the prey contents are dissolved before they can suck it empty.
Modern spiders crunch their catch with their jaws. Some spiders wrap their prey in silk, taking care that the victim does not bite them. Crab spiders do not use silk but use a rapid working poison. The injected enzymes dissolve the prey and then it is sucked empty.