Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Parkes Weber syndrome ?
    ### Response:
    Parkes Weber syndrome is a disorder of the vascular system, which is the body's complex network of blood vessels. The vascular system consists of arteries, which carry oxygen-rich blood from the heart to the body's various organs and tissues; veins, which carry blood back to the heart; and capillaries, which are tiny blood vessels that connect arteries and veins.
    