The endogenous cannabinoid system derived it's name from the plant that led to it's discovery. It is considered one of the most important physiological systems in the human and mamalian biologies. The Endocannabinoid receptors are found throughout different regions of the body including the brain, organs, connective tissues, glands, and immune cells. In each part of our body, the endocannabinoid receptors perform different functions, however the ultimate goal always remains the same; maintaining homeostasis and a stable internal environment.
Because of its crucial role in homeostasis, the ECS is widespread throughout the animal kingdom. Its key pieces evolved a long time ago, and the ECS can be found in all vertebrate species.
The three key components of the ECS are:
Endocannabinoids are molecules that, like the plant cannabinoid THC, bind to and activate cannabinoid receptors. However, unlike THC, endocannabinoids are produced naturally by cells in the human body (“endo” means “within,” as in within the body).
There are two major endocannabinoids: anandamide and 2-AG. These endocannabinoids are made from fat-like molecules within cell membranes, and are synthesized on-demand. This means that they get made and used exactly when they’re needed, rather than packaged and stored for later use like many other biological molecules.
Cannabinoids are a class of molecules characterized by their ability to activate cannabinoid receptors like CB1 and CB2. Anandamide and 2-AG are the two major endocannabinoids produced naturally in the body. THC is the psychoactive plant cannabinoid produced by Cannabis. All three of these cannabinoids can activate the CB1 and CB2 receptors, although each one has a different potency at each receptor.
Cannabinoids promote homeostasis at every level of biological life, from the sub-cellular, to the organism, and perhaps to the community and beyond. Here's one example: autophagy, a process in which a cell sequesters part of its contents to be self-digested and recycled, is mediated by the cannabinoid system. While this process keeps normal cells alive, allowing them to maintain a balance between the synthesis, degradation, and subsequent recycling of cellular products, it has a deadly effect on malignant tumor cells, causing them to consume themselves in a programmed cellular suicide. The death of cancer cells, of course, promotes homeostasis and survival at the level of the entire organism
Endocannabinoids and cannabinoids are also found at the intersection of the body's various systems, allowing communication and coordination between different cell types. At the site of an injury, for example, cannabinoids can be found decreasing the release of activators and sensitizers from the injured tissue, stabilizing the nerve cell to prevent excessive firing, and calming nearby immune cells to prevent release of pro-inflammatory substances. Three different mechanisms of action on three different cell types for a single purpose: minimize the pain and damage caused by the injury.