Question

1130 exam 2: chapters 19,17, and 20 (2 attempts) 21 a child hanging upside down from a tree takes a bite from a candy bar. they manage to chew the candy and swallow it successfully. how does the bolus move along the esophagus? multiple choice peristalsis of the esophageal walls force the bolus to the stomach. the pharyngeal constrictor muscles push the bolus into the esophagus and force it to remain there until the child returns to an upright position, when gravity can move it to the stomach. the epiglottis pushes the bolus into the esophagus and forces it to remain there until the child returns to an upright position, when gravity can move it to the stomach. pressure changes due to inhalation draw the bolus through the esophagus.

Explanation:

Peristalsis is the rhythmic contraction and relaxation of the smooth muscles in the esophageal walls. This process is involuntary and propels the bolus (the chewed and swallowed food mass) towards the stomach, regardless of the body's position (even when upside - down). The pharyngeal constrictor muscles are mainly involved in the pharyngeal phase of swallowing (moving food from the pharynx to the esophagus), not in moving the bolus along the esophagus. The epiglottis is a flap that prevents food from entering the trachea during swallowing, not related to moving the bolus in the esophagus. Pressure changes due to inhalation are not the mechanism for moving food in the esophagus.

Answer:

Peristalsis of the esophageal walls force the bolus to the stomach.