Final answer:
Nicotine affects the autonomic nervous system by stimulating both sympathetic and parasympathetic ganglia, leading to increased blood pressure and alterations in heart rate regularity. Its effects are similar to and different from curare, another substance that interacts with acetylcholine receptors. These effects explain some physiological consequences of smoking, such as the development of cardiovascular disease and arrhythmias.
Step-by-step explanation:
Nicotine, the active chemical constituent in tobacco, has broad effects on the autonomic nervous system. It stimulates both sympathetic and parasympathetic ganglia, leading to increased blood pressure and alterations in heart rate regularity, which are risk factors for cardiovascular disease. Nicotine exerts its effects by binding to nicotinic acetylcholine receptors, resulting in various downstream effects in the brain.
The effects of nicotine on the nervous system are similar to and different from those of curare. Both nicotine and curare interact with acetylcholine receptors, but nicotine acts as an agonist, while curare acts as an antagonist. Nicotine stimulates these receptors, leading to increased neuronal activity, while curare blocks their activation, resulting in muscle paralysis.
These effects of nicotine on the nervous system explain some of the physiological consequences of smoking. The increased sympathetic input from nicotine leads to higher blood pressure, which contributes to the development of cardiovascular disease. Additionally, the alterations in heart rate regularity caused by nicotine can result in arrhythmias. Overall, these effects highlight the negative impact of nicotine on the body and the importance of smoking cessation.