Peanut kernels and watermelon seeds and, rarely, other foreign bodies in the bronchi produce obstructive emphysema of the invaded side. Fluoroscopy shows the diaphragm flattened, depressed and of less excursion on the invaded side; at the end of expiration, the heart and the mediastinal wall move over toward the uninvaded side and the invaded lung becomes less dense than the uninvaded lung, from the trapping of the air by the expiratory, valve-like effect of obliteration of the "forceps spaces" that during inspiration afford air ingress between the foreign body and the swollen bronchial wall. This partial obstruction causes obstructive emphysema, which must be distinguished from compensatory emphysema, in which the ballooning is in the unobstructed lung, because its fellow is wholly out of function through complete "corking" of the main bronchus of the invaded side. _Esophageal Foreign Body_.--After initial choking and gagging, or without these, there may be a subjective sense of a foreign body, constant or, more often, on swallowing. Odynphagia and dysphagia or aphagia may or may not be present. Pain, sub-sternal or extending to the back is sometimes present. Hematemesis and fever may occur from the foreign body or from rough instrumentation. Symptoms referable to the air-passages may be present due to: (1) Overflow of the secretions on attempts to swallow through the obstructed esophagus; (2) erosion of the foreign body through from the esophagus into the trachea; or (3) trauma inflicted on the larynx during attempts at removal, digital or instrumental, the foreign body still being present or not. Diagnosis is by the roentgenray, first without, then, if necessary, with a capsule filled with an opaque mixture. Flat objects, like coins, always lie with their greatest diameter in the coronal plane of the body, when in the esophagus; in the sagittal plane, when in the trachea or larynx. Lateral, anteroposterior, and sometimes also quartering roentgenograms are necessary. One taken laterally, low down on the neck but clear of the shoulder, will often show a bone or other semiopaque object invisible in the anteroposterior exposure. [149] CHAPTER XIII--FOREIGN BODIES IN THE LARYNX AND TRACHEOBRONCHIAL TREE The protective reflexes preventing the entrance of foreign bodies into the lower air passages are: (1) The laryngeal closing reflex and (2) the bechic reflex. Laryngeal closing for normal swallowing consists chiefly in the tilting and the closure of the upper laryngeal orifice. The ventricular bands help but slightly; and the epiglottis and the vocal cords little, if at all. The gauntlet to be run by foreign bodies entering the tracheobronchial tree is composed of: 1. Epiglottis. 2. Upper laryngeal orifice. 3. Ventricular bands. 4. Vocal cords. 5. Bechic blast.