Cannabis, also known as marijuana, is a plant that contains various chemicals called cannabinoids. The most well-known cannabinoid found in cannabis is THC (tetrahydrocannabinol), which is responsible for the plant's psychoactive effects. When cannabis is consumed, whether by smoking, vaping, or ingesting it in edibles, THC binds to receptors in the brain and body's endocannabinoid system.

The endocannabinoid system is a complex network of receptors found throughout the brain and body that plays a role in regulating various physiological processes like mood, memory, appetite, and pain sensation. When THC binds to these receptors, it can alter how neurotransmitters are released in the brain, leading to changes in perception, mood, and behavior.

The effects of cannabis on the body can vary depending on factors like the potency of the strain consumed, the method of consumption, and an individual's tolerance level. Some common short-term effects of cannabis use include feelings of euphoria or relaxation, heightened sensory perception, increased appetite (commonly referred to as "the munchies"), impaired coordination and concentration, and altered time perception.

While many people use cannabis recreationally for its psychoactive effects, it also has potential therapeutic benefits. Medical marijuana has been used to treat conditions like chronic pain, nausea and vomiting associated with chemotherapy, muscle spasms caused by multiple sclerosis (MS), epilepsy, and anxiety disorders.

However, it's important to note that cannabis can also have negative effects on the body. Long-term heavy use of marijuana has been linked to cognitive impairments like memory loss and decreased attention span. Additionally, smoking cannabis can have negative effects on respiratory health similar to tobacco smoke.

In conclusion, cannabis affects the body by interacting with the endocannabinoid system and altering neurotransmitter activity in the brain. While it can produce both positive and negative effects depending on how it's consumed and an individual's tolerance level, more research is needed to fully understand its long-term impact on health.