Physiology As deglutition involved voluntary and involuntary stages, so among the following, which structure limits the size of bolus swallowed: A Soft palate B Posterior pharyngeal pillars C Upper esophageal sphincter D Larynx 💡 Explanation As deglutition involved voluntary and involuntary stages, so among the following, which structure limits the size of bolus swallowed: ✓ Correct Answer: B. Posterior pharyngeal pillars