Question

Why are hormones called chemical messenger?

Answer 1

They are signaling molecules and are synthesized within the body that regulate and coordinate physiological and metabolic functions by acting on receptors located on or in target cells. They can be created by specific secretory cells that are either localized in secretory organs

Complete step by step answer:
Hormones are called chemical messengers because they are chemical agents that go around the body to tell particular cells to play out a specific action. The term hormone depicts an assortment of chemicals that perform these signaling tasks. Hormones can go from proteins to amino acids to steroids.
The body has an endocrine system that contains several glands. The glands secrete hormones when given a signal from the brain. Hormones are required for a scope of activities. When cells need energy, then some signal appetite, while others signal sex drive when sperm or eggs are made. Hormone molecules go in search of certain cells, and when they find the right one with the right hormone receptor, it instructs the cell to begin the process.

Additional information: The endocrine system shares its signaling and coordinating functions with the nervous system. Chemical messengers formed by nerve cells and released from the axonal endings for the most part act in an endocrine or paracrine style. When the neural signaling molecules are released into the synaptic gap to activate receptors on the adjacent cell membranes, they are called neurotransmitters. The specificity of the message is guaranteed both by the particularity of receptors on the postsynaptic membrane just as by the discrete physical arrangement between axon terminals of a particular sort of neuron and the receptors on the postsynaptic membrane of a specific cell. Neurotransmission is characterized by speed of message transmission (milliseconds) and restricted points of delivery, while hormones act over a longer period of time (seconds to hours) and are distributed diffusely through the extracellular liquid medium to an enormous number of targets.

Note: In neuroendocrine secretions or neurohormones, the neural signaling molecules are released into circulation. By the method of their signal transmission, these messengers behave like hormones, that is they reach their targets through circulation. The delivery of an endocrine message to particular targets is assured by the specificity of receptors on target cells rather than by a discrete physical apposition of the source of the message and its target. The antidiuretic hormone or arginine vasopressin and oxytocin are examples of neuroendocrine signaling molecules.