<prompt> Foreign body the common passage isRight main bronchusLeft main bronchusBronchiolesAlveoli  <response>: A. i.e. Right main bronchus 297 -Dhingra 4thForeign bodies Children - seeds, beans, tiny toys Adult - meat is the most common cause of obstruction Most common route by which a foreign body enters the nose is the anterior nares 179 - Maqbool 11th Commonest site of foreign bodies of food passage is at or just below the cricopharyngeal sphincter. 311 - Dhingra 4thMost foreign bodies enter the right bronchus because it is wider and more in line with tracheal lumen causes - atelectasis or check valve obstruction Double density sign of chest x-ray is a feature of left atrial dilatation Fish bone, chicken bone, needle or a denture may lodge in the pyriform fossa 