Complex sentence: The endocrine system is a control system of ductless endocrine glands that secrete chemical messengers called hormones that circulate within the body via the bloodstream to affect distant organes not include exocrine glands such as salivary glands, sweat glands and glands within the gastrointestinal tract.
Split into simpler sentences: The endocrine system is a control system of ductless endocrine glands that secrete chemical messengers called hormones that circulate within the body via the bloodstream to affect distant organs. It does not include exocrine glands such as salivary glands, sweat glands and glands within the gastrointestinal tract.