Assumptions. The leader's ability to lead is contingent upon various situational factors, including the leader's preferred style, the capabilities and behaviors of followers and also various other situational factors.
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class of psychoactive drugs. It is the world's most widely consumed psychoactive drug, but unlike many other psychoactive substances, it is legal and unregulated in nearly all parts of the world.hen caffeine is consumed, it antagonizes adenosine receptors; in other words, caffeine prevents adenosine from activating the receptor by blocking the location on the receptor where adenosine binds to it. As a result, caffeine temporarily prevents or relieves drowsiness, and thus maintains or restores alertness.
Dr. Harold Urschel, chief medical strategist of the Dallas-based addiction-management company EnterHealth.com, author of Healing the Addicted Brain, and fellow Psychology Today blogger, told me: Caffeine is quite addictive in the sense that it is a psychoacive substance. It stimulates certain chemical systems in the brain and this keeps you awake. If you use it on a daily basis, you develop a tolerance, just as you would to pain pills or other drugs.