In healthy people, aspiration of small quantities of material is common and rarely results in disease or injury. People with significant underlying disease or injury are at greater risk for developing respiratory complications following pulmonary aspiration, especially hospitalized patients, because of certain factors such as depressed level of consciousness and impaired airway defenses (gag reflex and respiratory tract antimicrobial defense system). The lumen of the right main bronchus is more vertical and slightly wider than that of the left, so aspirated material is more likely to end up in this bronchus or one of its subsequent bifurcations.