Basic and Clinical Sciences Examination (BCSE) Practice Exam 2025 – Comprehensive All-in-One Guide for Exam Success

Nicotine is the substance found in tobacco that is primarily associated with its addictive properties. It functions as a potent psychoactive agent that stimulates the release of neurotransmitters, particularly dopamine, in the brain. This release creates pleasurable sensations, reinforcing the behavior of smoking and leading to the development of dependence. Over time, individuals may find themselves needing to consume nicotine regularly to avoid withdrawal symptoms, which further solidifies its addictive nature.

In contrast, carbon monoxide primarily contributes to the harmful effects of smoking on cardiovascular health, but it does not have a significant role in addiction. Nitrogen is a major component of tobacco smoke but does not have any pharmacological effects that contribute to addiction. Tar refers to the particulate matter in tobacco smoke that can lead to respiratory diseases and is more related to the carcinogenic aspects of smoking rather than its addictive properties. Thus, nicotine is the key player in the addictive characteristics of tobacco products.