Resident Manual of Trauma to the Face, Head and Neck

1. Right Main Bronchus The right main bronchus is shorter, wider, and more vertical than the left. It divides into three lobar bronchi and 10 segmental bronchi: three in the superior lobe, two in the middle lobe, and five in the inferior lobe. 2. Left Main Bronchus The left main bronchus divides into two lobar bronchi and eight seg- mental bronchi: four in the superior lobe and four in the inferior lobe. Anatomic variations may be present. C. Alimentary Tract 1. Hypopharynx The hypopharynx begins at the level of the hyoid bone. It is divided into the pyriform sinuses, the postcricoid region, and the posterior pharyn- geal wall. 2. Esophagus In adults the esophagus starts at the level of the cricopharyngeus or the upper esophageal sphincter, and ends at the lower esophageal sphinc- ter. It is approximately 22 centimeters (cm) long and has three points of anatomic constriction: (1) the cricopharyngeal sphincter (16 cm from incisors), (2) the left main stem bronchus (27 cm from the incisiors), and (3) the gastroesophageal junction (38 cm from the incisors). The cricopharyngeal sphincter is the narrowest point and is at highest risk of injury or perforation. 3. Stomach The stomach is divided into the cardia, fundus, body, and pylorus. The cardiac notch is the acute angle between the intra-abdominal esopha- gus and the gastric fundus. II. Foreign Bodies Although the incidence of aerodigestive foreign bodies has remained stable, its recognition and safety in removal have increased dramati- cally. The majority of foreign bodies are esophageal in both children and adults. Airway foreign bodies are more likely to occur in children. A higher incidence is found in children due to lack of molars, less con- trolled coordination of swallowing, immaturity in laryngeal elevation and glottic closure, and their tendency to explore their environment by putting things in their mouth.

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