[Campbell Biology P.955] Based on Figure 41.9 and the accompanying text, which of the follow... | Practice Question

Based on Figure 41.9 and the accompanying text, which of the following accurately describes the events during swallowing that prevent food from entering the respiratory tract?

  • A: The esophageal sphincter contracts to seal off the esophagus, while the epiglottis moves up to cover the trachea.
  • B: The glottis opens wide, allowing food to pass directly into the trachea, then into the esophagus.
  • C: The epiglottis tips down, covering the opening of the trachea, and the esophageal sphincter relaxes to allow the bolus into the esophagus.
  • D: Peristaltic contractions in the pharynx forcefully push the bolus past both the trachea and esophagus simultaneously.

Explanation

The text clearly states: 'Movement of the larynx, the upper part of the airway, tips a flap of tissue called the epiglottis down, preventing food from entering the trachea. At the same time, the esophageal sphincter relaxes, allowing the bolus to pass into the esophagus.' This perfectly matches option C.