Fill in the Blank QuestionFill in the blank question.The auricles are flap-like projection off of the and serve to increase their blood volume.

The correct answer to fill in the blank in the given statement is atria.

Explanation:

The auricles, also known as auricular appendages, are muscular pouches attached to the atria of the heart. There are two auricles in the heart—one associated with the right atrium and one with the left atrium. Their main function is to increase the capacity of the atria, allowing them to hold a larger volume of blood. When the blood returns to the heart from the body or lungs, the auricles expand to accommodate this volume, facilitating efficient blood flow into the ventricles. This anatomical feature plays an important role in the heart's overall efficiency and ability to manage the volume of blood being circulated through the body.

In summary, the completed statement reads: "The auricles are flap-like projections off of the atria and serve to increase their blood volume."