Nicotine

The main alkaloid (a nitrogenous compound such as lipids) in tobacco, it is ingested when tobacco is smoked or chewed, or snuff taken.  It is a strong stimulant of the nicotine acetylcholine receptors, especially those in the ganglia of the autonomic nervous system, that raises blood pressure, reduces sensory feedback from muscle spindles and muscle tone, and in large doses can induce tremors, convulsions and fluid retention.  Its molecules are small enough to cross the placenta, and the carbon monoxide the mother inhales during cigarette smoking reduces oxygen supply to the fetus. Together with the more than 2000 chemical compounds in cigarette smoke, it can be one of the causes of intrauterine growth restriction, as well as spontaneous abortion and stillbirth, if the mother smokes during pregnancy.  Named after Jacques Nicot (1530-1600), a diplomat, who introduced tobacco into France in 1560.

See Acetylcholine (AcH), Autonomic nervous system (ANS), Carboxyhemoglobin (CoHb), Cardiovascular accidents (CVAs), Dopamine, Emphysema, Environmental tobacco smoke (ETS), Ganglia, Intrauterine growth restriction or retardation (IUGR), Lipids, Mesencephalic reticular activating system, Muscle spindle, Muscle tone (or power), Placenta, Vasoconstriction