22Name the main psychoactive constituent of the cannabis plant AND briefly describe its action mechanism.

The main psychoactive constituent of the cannabis plant is Delta-9-tetrahydrocannabinol (THC).

THC's action mechanism involves its interaction with the endocannabinoid system in the brain. This system is a group of neuromodulatory lipids and their receptors, which are involved in a variety of physiological processes including appetite, pain sensation, mood, and memory.

THC binds to cannabinoid receptors, particularly the CB1 receptor, which are predominantly found in the brain. This binding mimics the action of endocannabinoids, which are naturally occurring substances in the brain. The binding alters the release of neurotransmitters in the brain, leading to changes in perception, mood, memory, and appetite. This is what causes the 'high' or the psychoactive effects associated with cannabis use.