The Endocannabinoid System

Back in high school, I took a course on human anatomy. There we learned about the 11 organ systems in the human body; the circulatory system, digestive system, endocrine system, integumentary system/ exocrine system, immune system and lymphatic system, muscular system, nervous system, renal and urinary system, reproductive system, respiratory system, and skeletal system. Notice how the endocannabinoid system was not mentioned and yet it plays a significant role in almost all the systems listed above. 

So what is the endocannabinoid system, and why is it so crucial to our health and well-being? 

The endocannabinoid system is the most important physiologic system involved in establishing and maintaining human health. It affects a wide variety of biological processes; however, its overall function is to regulate homeostasis. 

• Homeostasis – maintaining physiological (the normal functions of living organisms and their parts) stability 

If it weren’t for the research of cannabis, the endocannabinoid system would not have been discovered. In 1964 researchers discovered a cannabinoid in cannabis known as THC (the cannabinoid that gets you high). After discovering THC, researchers wanted to know what receptor in the body that it was interacting with to cause these effects. Then in the late 1980s, the first cannabinoid (CB) receptors in the human body were found, leading to the discovery of the endocannabinoid system.

The endocannabinoid system has 3 main elements:

• Cannabinoid receptors – receptors that, when signaled by endocannabinoids, activate a cascade of biochemical pathways. They are strategically distributed throughout our body, with a high concentration in our nervous and immune system
• Endocannabinoids – (endogenous = made internally) naturally occurring neurotransmitters or chemical messengers with the specific ability to engage with cannabis
  • body’s production of its own cannabinoids 
• Enzymes that either synthesis or metabolize – the builders & clean up crew of endocannabinoids 

Cannabinoid Receptors

• These receptors are distributed throughout the body in the central nervous and immune system, the brain, gastrointestinal system, reproductive and urinary tracts, spleen, endocrine system, heart, and circulatory system.
• They recognize and respond to 3 varieties of cannabinoids:
  • Endocannabinoids – what our body produces 
  • Phytocannabinoids – produced from cannabis 
  • Synthetic cannabinoids – created in a laboratory 
• There are 2 primary subtypes of classical cannabinoid receptors in the body
  • CB1
    • Mostly found in the central nervous
    • Mainly expressed in the brain 
    • The THC family of cannabinoids are the only compounds that robustly active CB1 receptors
  • CB2
    • Highly expressed throughout the immune system on immune cells
    • Has been identified in key regions of the brain
    • Found in the gastrointestinal system and peripheral nervous system
    • Control the release of cytokines (immunoregulatory proteins) linked to inflammation and general immune function

The endocannabinoid system is a regulatory system in the body, regulating diverse function such as 

• Memory
• Digestion
• Motor function 
• Appetite 
• Immune response and inflammation
• Pain
• Blood pressure
• Bone growth
• Protection of neural tissues 

The endocannabinoid system also affects brain functions, such as:

• Decision making
• Cognition
• Emotions
• Learning
• Memory
• Anxiety
• Stress
• Regulation of bodily movement
• Fear
• Pain
• Body temperature
• Appetite
• Blood-brain permeability 
• Motor control 
• Sense of reinforcement or reward