| A | B |
|---|
| addiction | A condition in which the body requires a drug; a combination of physical and psychological dependence |
| adrenal glands | Glands located above the kidneys that secrete hormones such as adrenaline, a stimulant |
| association neurons | Neurons found in the spinal cord and the brain that serve as links between sensory and motor neurons |
| bronchitis | A chronic inflammation of the bronchial tubes which causes severe coughing |
| carbon monoxide | A toxic gas found in tobacco smoke that reduces the amount of oxygen in red blood cells |
| dendrites | The short fibers in a neuron that carry messages toward the cell body |
| dopamine | A neurotransmitter in the brain that produces feelings of well-being |
| drug | A chemical that causes physical, chemical, emothional, or behavioral changes in the body |
| emphysema | A lung disease caused from permanent damage to the alveoli; causes coughing, wheezing, and shortness of breath |
| impulse | An electrical message that travels along a neuron |
| motor neurons | Neurons that carry impulses from the spinal cord or the brain to the body |
| nervous system | A control system of the body that is made up of the brain, spinal cord, and nerves |
| neurons | Nerve cells that carry electrical messages |
| neurotransmitter | A chemical in the brain that transmits messages |
| nicotine | A naturally-occuring, toxic ingredient in tobacco that increases heart rate and blood pressure |
| physical dependence | A condition where a person suffers from withdrawal when they stop using an addictive substance; the body no longer functions normally without it |
| psychological dependence | A mental or emotional need for a drug |
| secondhand smoke | Smoke that is inhaled by people around the smoker; it is more toxic than inhaled smoke |
| sensory neurons | Neurons that carry impulses from outside the body to the spinal cord or the brain |
| stimulant | Substance that increases the activity of the nervous system |
| synapse | A gap between two neurons |
| tar | A sticky, yellow-brown substance that stains the fingers, teeth, and lungs of smokers; it is one of the main carcinogens in cigarettes |
| tobacco | A plant cultivated for its leaves, which are used primarily for smoking and products such as snuff |
| tolerance | A condition in which higher doses of a drug are needed to produce the same effect; it often leads to addiction |
| trachea | A tube in the throat that carries air from the larynx toward the lungs |
| withdrawal | A condition in which the body reacts to the absence or reduction of an addictive substance with symptoms such as headaches, nausea, shaking, etc. |
