What does the oral preparatory phase initiate?

• A. Coordinated series of reflexes in the pharynx
• B. Peristaltic waves in the esophagus
• C. Airway protection reflex only
• D. Swallowing reflex only

Answer: (A)

The important idea here is that swallowing is a stepwise process with both voluntary and reflexive parts. In the oral preparatory phase, you chew and mix saliva to form a cohesive bolus, keeping it in the mouth and ready for swallowing. When the bolus is ready, sensory input triggers the swallow, which sets off a coordinated sequence of reflexes in the pharynx. This pharyngeal reflex sequence includes airway protection and propulsion of the bolus into the esophagus, all happening in a tightly coordinated burst.

So, the oral preparatory phase initiates a coordinated set of pharyngeal reflexes that move the process from preparation to the actual swallow. Peristaltic waves in the esophagus occur later, during the esophageal phase. Airway protection reflexes are part of the pharyngeal swallow but aren’t the sole function, and the swallowing reflex is part of that pharyngeal sequence rather than something started only by the oral preparatory phase.