Necessary for Vitamin B12 absorption, ________  is/are secreted by ________ cells.

Necessary for Vitamin B12 absorption, ________  is/are secreted by ________ cells.

Acid reflux into the esophagus (“heartburn”) is normally prevented by ________.

The small intestine uses segmentation to mix chyme with digestive enzymes, increase its contact with the mucosa, and propel it forward through the digestive tract. 

The ________ regulates the flow of contents from the stomach to the duodenum.

Pepsinogen is produced by ________ and is activated by ________, which is secreted by ________.

Which of the following is not an accessory organ of digestion?

The small intestine is suspended from the abdominal wall by the ________.

The rate of oxygen diffusion is affected by the pressure gradient of carbon dioxide.

Which of the following is not a process carried out by bacterial flora?