Pop quiz: Can you recall the 11 major organ systems in the human body? If not, don’t sweat it. You’re not alone. It’s hard enough to remember the name of someone I just met, nevermind a health and science lesson from 20+ years ago.

Here’s a quick refresher.

They are: circulatory, respiratory, urinary, reproductive, integumentary, skeletal, muscular, nervous, endocrine, digestive, and lymphatic.

But there’s another physiologic system that, while lesser-known, is by no means less important. In fact, experts say it is crucial to establishing and maintaining health. When it comes to keeping your body operating optimally, the ECS is the MVP.

Most of us didn’t learn about the ECS in grade school. And unless you studied health or medicine in college, you may not have heard about it there either. This is partly because even researchers didn’t know about the ECS’ existence until the 1990s. Three decades later, we still have much to learn about it and its role. But the story so far is one everyone should hear.


The ECS got its name from the word “cannabinoid,” which comes from cannabis, and “endo,” short for endogenous, which means that something naturally occurring in the body. Scientists identified the cannabinoids in cannabis, including THC, and sought to learn more about how they interact with the human body. This led them to the discovery of the ECS.

Here’s what they’ve learned.

The ECS is an intricate network that includes compounds (endocannabinoids) closely resembling those in the cannabis plant and receptors and enzymes. The cannabinoids in cannabis, including THC and CBD, mimic endocannabinoids and these compounds bind with receptors located in the nervous system and around the body.

Thus far, researchers have identified two key endocannabinoids: anandamide (AEA) and 2-arachidonoylglyerol (2-AG). These help the body maintain homeostasis in various areas, and the body produces them as needed. These endocannabinoids, and the ECS generally, are active whether or not you use cannabis.


CBD (cannabidiol) and THC (Tetrahydrocannabinol) are two of more than 100 phytocannabinoids (plant-produced cannabinoids) in cannabis plants. When these phytocannabinoids enter the body, they mimic endocannabinoids and stimulate the ECS, correcting ECS deficiencies and helping it to work more effectively.

Researchers are still learning about the ECS and how it works. But we do know it is responsible for regulating an array of functions and processes, including:

  • Sleep
  • Mood
  • Appetite
  • Digestion
  • Memory
  • Reproduction and fertility
  • Immune response
  • Inflammation (including neuroinflammation)
  • Temperature regulation
  • Stress (including anxiety)
  • Pain
  • Pleasure/reward
  • Motor control

The ECS is responsible for ensuring everything is operating as it should. Think of it this way: if your body was a computer, the brain might be the Motherboard, while the ECS is the CPU (central processing unit). If something isn’t quite right, the ECS steps in to get it back on track. This can include your overheating, imbalance hormones, fatigue, hunger, anxiety, or a buildup of something in the bloodstream. When it’s operating optimally, the ECS is precise and efficient, administering targeted aid to the areas that need it.

How does the ECS know when something’s up? It receives signals via cannabinoid receptors, of which there are at least two types. The CB1 receptors are located in the central nervous system, while the CB2 receptors are located in the peripheral nervous system (including the digestive system, immune system, and nerves in the extremities).

When the ECS gets its call to action, it produces endocannabinoids to address the problem and restore homeostasis (balance) to the body. Once all is well again, enzymes break down the endocannabinoids to prevent things from going too far and tilting the scales in the opposite direction.

Homeostasis is crucial to our wellbeing and survival. So when the ECS isn’t working as it should, things can go haywire. Scientists use the term clinician endocannabinoid deficiency (CECD) to refer to several conditions related to a dysfunctional ECS, including but not limited to fibromyalgia, migraines, and irritable bowel syndrome.

Even if CECD is not a factor, the ECS can influence an array of conditions. Improving the ECS’ function can improve ailments ranging from chronic pain and inflammation to anxiety and insomnia to epilepsy. An efficient ECS can also help reduce stress, boost energy, and speed up recovery time, among other benefits.


CBD and THC can have a range of health benefits when consumed independently or together. THC interacts with both CB1 and CB2 receptors, while CBD primarily influences CB2 receptors. Because of this, they have different effects on the body.

CBD is usually used for ailments such as pain and inflammation, nausea, seizures, migraines, mental illnesses such as anxiety and depression, and sleep disorders.

On the other hand, THC is most often used for low appetite, muscle spasms, pain, glaucoma, insomnia, nausea, and anxiety.

Many people use a combination of the two to get the full range of health benefits. But CBD packs plenty of power on its own too.