Answer
Hormones are defined as the chemical substances produced by body to play the role of messengers. These are transported through body fluids like blood.
Hormones are produced by endocrine glands in Human body. Once produced, these are released in blood so that they can reach and act on their target tissue or organ.
Ex: Thyroxine
Hormones belong to endocrine system whereas neurotransmitters belong to nervous system.
Work Step by Step
How to distinguish between hormone and neurotransmitters?
• Hormones are found in blood where as neurotransmitters are found only at synapses
• Hormones act on a distant site from where it is produced whereas neurotransmitters act in direct apposition to their target cells
• Hormones take a few minutes or a few days to reach their target organ and act upon them. On the other hand, neurotransmitters act within milliseconds on their target receptors
• Hormones have diverse functions whereas neurotransmitters are used only to transmit nerve signals
This is an imperfect distinction because-
For example, consider norepinephrine. It is produced by adrenal gland which is an endocrine gland. Hence, it is a hormone which acts as a neurotransmitter. When considered the structures of neurotransmitters and hormones, many of them are polypeptides and amino acids. Because of close similarities of neurotransmitters and hormones, it is an imperfect distinction.
