Hormones exist throughout nature. All multicellular organisms both plant and animal- produce hormones. In fact, in all animals nearly early every tissue and organ system produces hormones, and in all cases those hormones act as chemical messengers that relay information and instructions from one individual or group of cells to another.
Hormones act as signal cells, and they pass that signal by traveling through the body. In most cases, hormones travel through the body in the body’s blood stream. But other hormones ectohormones- bypass the bloodstream and travel to neighboring cells in a process called diffusion. In both cases, the hormones send signals to other cells; signals that changes are about to happen.
Hormones initiate changes in cells when the hormones combine with specific receptors on the target cells. In most cases, the hormone receptor is embedded on the surfaced membrane of the targeted cells. When the hormone arrives at its destination cell, the hormone and receptor interact and initiate a series of effects within the cells’ cytoplasm. Cytoplasm is the water-like substance that fills the cell.
The effect of hormones varies greatly and is dependent on the type of hormone that is in action. Hormones can stimulate or inhibit growth, induce the death of a cell, activate or inhibit the immune system, regulate metabolism, control reproductive organs, or prepare the body for new phases of life (like aging, or puberty). Hormones can even regulate the production and release of other hormones.
All of those activities are initiated by hormones, but the hormones themselves are controlled by other elements of the body. Hormone secretion can be stimulated by other hormones, nutrients, mental activities, and environmental changes. But despite the myriad functions of hormones, they can be classified into three basic categories. Amine-derived hormones are derivatives of amino acids (such as many thyroid hormones). Peptide hormones consist of chains of amino acids. The best known peptide hormones are insulin and growth hormones. Lastly there is lipid and phospholipids-derived hormones such as the steroid hormones, like cortisol, and testosterone.
Hormones play many roles in the body, but sometimes natural production is not sufficient and people must turn to pharmacology to obtain the levels needed for a healthy existence. Commonly prescribed hormones are estrogen and progestagens (often for contraception), insulin, thyroxine (for thyroid disorders), and steroids which are used to combat autoimmune diseases as well as respiratory disorders.
Hormones play an incredibly important role in the functioning of all living things. Whether naturally produced, or supplemented from another source, hormones are the instant messengers of life.