Vancouver has recently experienced conflicts with other Clark County communities because of rapid growth in the area. The city's first annexation more than doubled its size in 1909, with the largest annexation of 1997 adding 11,258 acres (45.56 km 2) and 58,171 residents.
Why is nicotine addictive? When you use tobacco products, nicotine is quickly absorbed into your bloodstream. Within 10 seconds of entering your body, the nicotine reaches your brain. It causes the brain to release adrenaline, creating a buzz of pleasure and energy. The buzz fades quickly though, and leaves you feeling tired, a little down, and wanting the buzz again. This feeling is what makes you light up the next cigarette.
Your brain is made up of billions of nerve cells. They communicate by releasing chemical messengers called neurotransmitters. Each neurotransmitter is like a key that fits into a special lock, called a receptor, located on the surface of nerve cells. When a neurotransmitter finds its receptor, it activates the receptor's nerve cell. The nicotine molecule is shaped like a neurotransmitter called acetylcholine. Acetylcholine and its receptors are involved in many functions, including muscle movement, breathing, heart rate, learning, and memory. They also cause the release of other neurotransmitters and hormones that affect your mood, appetite, memory, and more. When nicotine gets into the brain, it attaches to acetylcholine receptors and mimics the actions of acetylcholine. Nicotine also activates areas of the brain that are involved in producing feelings of pleasure and reward. Recently, scientists discovered that nicotine raises the levels of a neurotransmitter called dopamine in the parts of the brain that produce feelings of pleasure and reward. Dopamine, which is sometimes called the pleasure molecule, is the same neurotransmitter that is involved in addictions to other drugs such as cocaine and heroin.