Which of the following statements is correct in relation to the endocrine system?

Hormones are non-nutrient chemicals produced by the body in trace amounts that act as intercellular messengers.

Hormones are not considered nutrients, as they do not provide energy or serve as building blocks for the body. Instead, hormones act as signals to coordinate various physiological functions, such as growth, metabolism and reproductive processes.

Hormones are produced in trace amounts because they are highly potent and are designed to produce a response in the target tissues at low concentrations. The trace amounts of hormones present in the bloodstream are sufficient to produce a response in the target tissues without over-stimulating them.

(2) Releasing and inhibiting hormones are produced by the hypothalamus and they regulate the anterior pituitary.

(3) Neurohypophysis is under direct neural regulation of the hypothalamus. 

(4) Organs in the body, like gastrointestinal tract, heart, kidney and liver, do produce hormones. Gastrointestinal tract produces many hormones, like gastrin, secretin, cholecystokinin etc. The heart produces ANF. The kidneys produce erythropoietin. The liver produces thrombopoietin, IGF-1, angiotensinogen (a precursor of hormone angiotensin) etc.