The structure of the esophagus fits its function in that
A) it can direct food to the lungs or stomach.
B) it has smooth muscle for peristalsis.
C) it is regulated by contractions in the pharynx.
D) its length determines the volume of food an animal can ingest.

Question

Quizplus · Accepted Answer

The esophagus has smooth muscle that contracts to move food down towards the stomach through peristalsis. This is necessary to ensure that food is moved in the correct direction and is not directed towards the lungs. Contractions in the pharynx are important in initiating swallowing, but they do not regulate the esophagus itself. The length of the esophagus may vary among species, but it does not directly determine the volume of food an animal can ingest.

The Structure of the Esophagus Fits Its Function in That