Endocrine Hormones Are Involved in Blood Pressure Homeostasis The human body is probably as scientific as it could be with a whole network of well-placed checks and balances. We have the nervous system and the immune system and these systems are there to stay and more importantly, they evolve and change as time goes by. They continue to update themselves and this is what keeps man abreast of everything else and the changes as they occur. The hormone is like a messenger or a communicator in the case of our body. Once released, it carries the message back and forth and travels through the main bloodstream until it reaches and finds a cell with a suitable receptor. This must fit perfectly and that is why it is a given that it must attach to the molecule like a key made for a certain lock. Then, like a key in a lock, the molecule attaches to the receptor and sends a signal inside the cell, which is then retransmitted. It is the content of the message that implies whether to produce, release, absorb or reduce the supply of p...