They may experience irritability and depression because when a person constantly smokes, his/her brain begins to rely on the chemicals it gets from the person smoking, which results in the brain "getting lazy" and not producing the chemicals anymore. If the person were to suddenly quit, the brain would lack in the chemicals it had stopped producing, making the person feel constantly annoyed and depressed because of the chemical imbalance.
Premenstrual syndrome affects a high percentage of woman of childbearing age with many woman feeling mood changes in the day before menstruation
The arteries carry oxygenated blood away from heart and then re-takes it back to your system
