The Pathway. 1  Air enters the nostrils. 2  passes through the nasopharynx, 3  the oral pharynx.  through the 1  glottis. into the trachea.  into the right and left bronchi, which branches and rebranches 1  into. bronchioles, each of which terminates in a cluster  of. alveoli.
As the body adjusts to less caffeine, these symptoms should subside. Nicotine May Cause Less Sleep. Nicotine is also a stimulant, and nicotine side effects can cause insomnia and withdrawal symptoms similar to caffeine. Smoking may also create other sleep disturbances.
Unless that level is maintained, the body will begin to go through withdrawal. For tobacco users trying to quit, symptoms of withdrawal from nicotine are unpleasant and stressful, but only temporary. Most withdrawal symptoms peak 48 hours after you quit and are completely gone in six months.