Smoking has two different effects on our nervous system. The nicotine in tobacco can act as a stimulant to the sympathetic nervous system and as a depressant.
The sympathetic system is tasked with keeping our heart beating and taking the body to a state of heightened readiness. The sympathetic system is linked to “flight or flight” systems in the body. In contrast, the parasympathetic system is linked to “rest and digest” systems of the body. Our ability to sense hunger, and the spontaneous salivation to the smell of a croissant with bacon, egg, and cheddar cheese is made possible the parasympathetic system.
On the stimulation side of the nervous system, nicotine makes the heart beat faster, raises blood pressure, and increases the rate of breathing.
On the rest-and-digest side of the nervous system, nicotine can promote excessive salivation and alters the natural digestive process. Here, nicotine inhibits hunger and deadens the taste buds. The havoc that nicotine plays with the parasympathetic nervous system is linked to smokers loss of appetite. For some smokers, this loss of appetite, taste, and reduced sense of smell can lead to weight loss.
Like cutting the brake lines of an automobile and accelerating downhill. Smoking tobacco turns up the speed of the heart, respiration, and muscle tension. Paradoxically, smoking blunts the ability of the rest-and-digest activities. Smoking reduces the ability of the parasympathetic system to provide smooth muscle control and down regulate heart rate, thus removing fine control of the body and mind.
Relevant Reading