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.
Nicotine withdrawal symptoms can be controlled with smoking cessation products such as nicotine gum, lozenges, or patches. Some people find that stopping caffeine consumption abruptly results in headaches and fatigue. Caffeine is also present in tea, some soft drinks, certain medications, and chocolate.