Ans.Emphysema
Emphysema is the destruction of the walls of the alveoli. It results in larger sacs but with less surface area of gaseous exchange. As lung tissue breaks down, the lungs do not come back to their original shape after exhalation. So air cannot I pushed out and is trapped in the lungs.
Sign and Symptoms
The symptoms of emphysema include shortness of breath, fatigue, recurrent respiratory infections and weight loss. By the time the symptoms of emphysema appear,the patient has usually lost 50% to 70% of his/her lung tissue. The level of oxygen in blood may get so low that it causes serious complications. Figure 10.7.