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.
After two hours without a cigarette, your heart rate and blood pressure will have decreased to near normal levels. Your peripheral circulation may also improve. The tips of your fingers and toes may start to feel warm. Nicotine withdrawal symptoms usually start about two hours after your last cigarette. Early withdrawal symptoms include: 1  intense cravings. 2  anxiety, tension, or frustration. 3  drowsiness or trouble sleeping. 4  increased appetite.