title: Biological factors underlying the smoking habit.
mesh_terms: D002248:Carbon Monoxide / Q000009:adverse effects / Q000494:pharmacology*; D002319:Cardiovascular System / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D006801:Humans; D009042:Motivation; D009538:Nicotine / Q000009:adverse effects / Q000494:pharmacology*; D012054:Reinforcement, Psychology; D012907:Smoking; D019966:Substance-Related Disorders / Q000209:etiology; D013638:Tars / Q000009:adverse effects / Q000494:pharmacology*
chemical_list: D013638:Tars; D009538:Nicotine; D002248:Carbon Monoxide