While lying supine in bed eating, a child aspirates a peanut. Which of the following bronchopulmonary segments would this foreign object most likely enter?

Foreign body Later symptoms are caused by airway obstruction, inflammation or trauma induced by the foreign body and would depend on the site of its lodgement. (a) Laryngeal foreign body. A large foreign body may totally obstruct the airway leading to sudden death unless resuscitative measures are taken urgently. A paially obstructive foreign body will cause discomfo or pain in the throat, hoarseness of voice, croupy cough, aphonia, dyspnoea, wheezing and haemoptysis. (b) Tracheal foreign body. A sharp foreign body will only produce cough and haemoptysis. A loose foreign body like seed may move up and down the trachea between the carina and the undersurface of vocal cords causing "audible slap" and "palpatory thud." Asthmatoid wheeze may also be present. It is best heard at patient's open mouth. (c) Bronchial foreign body. Most foreign bodies enter the right bronchus because it is wider and more in line with the tracheal lumen. A foreign body may totally obstruct a lobar or segmental bronchus causing atelectasis or it may produce a check valve obstruction, allowing only ingress of air but, not the egress, thus leading to obstructive emphysema. Emphysematous bulla may rupture causing spontaneous pneumothorax. A foreign body may also shift from one side to the other causing change in the physical signs. A retained foreign body in the lung may later give rise to pneumonitis, bronchiectasis or lung abscess. Ref : ENT textbook by Dhingra 6th edition Pgno : 321