Question

A food bolus progresses thru the esophagus when the inner cicular layer of the muscularis externa ____ on the oral side of the bolus and ________ on the stomach side of the bolus

Answer 1

The inner circular layer of the muscularis externa contracts on the oral side of the bolus and relaxes on the stomach side, allowing the bolus to move through the esophagus.

Step-by-step explanation:

The inner circular layer of the muscularis externa contracts on the oral side of the bolus and relaxes on the stomach side of the bolus. This contraction in the circular muscle layer pinches the esophageal wall and forces the bolus forward, while the relaxation allows the bolus to pass into the stomach. This process is part of peristalsis, which is the rhythmic contraction and relaxation of muscles that moves food through the esophagus.