However, when you want to compare a Boolean variable with the literal Boolean value true or false, it is not necessary to do an explicit comparison, because the result of evaluating a Boolean value is that Boolean value. For example, the expressions
The nicotine in cigarette smoke is a big part of the problem. It raises your blood pressure and heart rate, narrows your arteries and hardens their walls, and makes your blood more likely to clot. It stresses your heart and sets you up for a heart attack or stroke. Know Your Blood Pressure Numbers.
Once within the bloodstream, nicotine may circulate around the body until it reaches the brain. This can occur in as little as 7 seconds. Once in the brain, it binds to and activates receptors called the cholinergic receptors. These cholinergic receptors are also abundant in other areas of the body such as the muscles, heart, adrenal glands and other vital organs.