Nicotine

More people know that smoking cigarette is bad. But, for several people, they need to smoke to heightening alertness and concentration. How could this happen? In cigarette, there are many kinds of chemical, one of them is nicotine. Deep inhalation of nicotine-laden smoke results in rapid absorption of nicotine in the lungs, the nicotine diffuses into the bloodstream as rapidly as the inhaled oxygen. From the lungs the nicotine reaches the brain in less than 10 seconds. Nerve cells, or neurons, in the brain and peripheral nervous system have receptor proteins on their surfaces to which nicotine binds, much in the way that a key fits into a lock. When a molecule of nicotine binds to a nicotine receptor, it causes the neuron to transmit a nerve impulse to various target organs and tissues. This process stimulates the release of neurotransmitter, or chemical messengers, which produce the physiological and psychological effects of nicotine. For example, nicotine stimulates the adrenal glands and prompts the release of epineprhine and norepinephrine, which are responsible for raising heart rate and blood pressure and heightening alertness and concentration. Nicotine also stimulates the release of the neurotransmitter dopamine in the brain. Dopamine is thought to be critical to nicotine's reinforcing and pleasurable mood-altering effects.