Which module to start medcine with
Pleural effusion, obesity etc are external submisive factors that dampen the sound.
Pleural effusion’s fluid surrounds the lung and acts like a transmission barrier.
Now understand the difference between consolidated and collapse.
Consolidated is generally lobular and confined to a lobe. It’s generally following pneumonia and collapse is following and pneumothorax or any effusion etc.
In consolidated lung,the air channels or the bronchioles are intact.Hence air present in the bronchioles can still transmit the sound where as in collapse there is collapse of the bronchioles too so decreased sound.
Now why sound increases.
I am not that sure but in consolidation there is solidification of the lung following infection.
Hence the sound is magnified by a solid media.
In consolidation because of the same reason we get increased Bronchial breath sounds(vesicular breath sounds are absent as the alveoli is destroyed,but as a solid media is present the bronchial breath sound of the bronchioles and bronchi is magnified itself).
Hope it clears out some of ur doubt.
Note:- In consolidated lung the sounds overall are diminished in totality as the bronchioles also collapse.