Although the disc media and the drives of the CD and CD-ROM are, in principle, the same, there is a difference in the way data storage is organized. Two new sectors were defined, Mode 1 for storing computer data and Mode 2 for compressed audio or video/graphic data.
Emphysema Causes. Cigarette smoking is by far the most dangerous behavior that causes people to develop emphysema, and it is also the most preventable cause. Other risk factors include a deficiency of an enzyme called alpha-1-antitrypsin, air pollution, airway reactivity, heredity, male sex, and age. The pollutants cause inflammation in the airways, leading to lung tissue destruction. 2  Close relatives of people with emphysema are more likely to develop the disease themselves. 3  This is probably because the tissue sensitivity or response to smoke and other irritants may be inherited.
Emphysema destroys alveoli, which are air sacs in the lungs. The air sacs weaken and eventually break, which reduces the surface area of the lungs and the amount of oxygen that can reach the bloodstream. This makes it harder to breathe, especially when exercising. Emphysema also causes lungs to lose their elasticity. Emphysema is one of the two most common conditions that fall under the umbrella term chronic obstructive pulmonary disease (COPD). The other major COPD condition is chronic bronchitis. Emphysema is an irreversible condition, so treatment aims to slow its progression and minimize symptoms.