Final answer:
Nicotine is a stimulant with significant effects on the autonomic system, increasing sympathetic stimulation and leading to cardiovascular risks. While highly addictive and used in smoking cessation aids, it carries withdrawal symptoms and long-term health risks.
Step-by-step explanation:
Nicotine, an active chemical compound in tobacco, has significant pharmacological effects, particularly at low doses such as those from smoking 1 to 1½ packs per day. When nicotine enters the body, it influences the autonomic system, leading to a range of effects.
For example, nicotine stimulates both sympathetic and parasympathetic ganglia at the preganglionic fiber synapse. However, this results in increased sympathetic stimulation on the cardiovascular system, as the parasympathetic system has little effect on overall blood pressure, leading to an increase in blood pressure and potentially causing arrhythmias.
Despite its use in smoking cessation aids like patches and gum, nicotine remains highly addictive, with withdrawal symptoms such as headaches, irritability, and cravings. Its chronic use is associated with increased risks of heart disease, stroke, various cancers, and adverse effects associated with vaping. Understanding the effects of nicotine is crucial for the development of effective smoking cessation programs and treatments.