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 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.fter two or three weeks without smoking, your lungs may start to feel clear, and you'll start breathing easier (AHA, 2012) . For most smokers, withdrawal symptoms dissipate about two weeks after quitting.