Excretory systems of three major arthropod classe

Question

How are excretory systems of three major arthropod classes constituted?

Answer 1

In the crustaceans a couple of excretory organs which is called green glands. The green glands gather residuals from blood and other parts of body. They are linked by ducts to excretory pores situated under the base of antennae and these pores liberate excretions outside.

In the insects small structures named as malpighian tubules collects wastes from blood and throw them in excretory ducts that open in intestine. In these animals excretions are eradicated together with feces.
In the arachnids, as well malpighian tubules, there are coxal glands situated in cephalothorax near the limbs which also participate in the excretion.