Milady Esthetics State Board Practice Test 2025 - Free Esthetics Exam Practice Questions and Study Guide

An atrium is a chamber of the heart, specifically one of the two upper chambers that receive blood. In human anatomy, there are two atria: the right atrium and the left atrium. The right atrium receives deoxygenated blood from the body through the superior and inferior vena cavae, while the left atrium receives oxygenated blood from the lungs via the pulmonary veins. Understanding the function of the atria is crucial because they play a vital role in the cardiac cycle, facilitating the flow of blood into the lower chambers of the heart, known as the ventricles.

The other options refer to different organs where atria are not present: the lungs are responsible for gas exchange, the brain serves as the control center for the nervous system, and the stomach is involved in digestion. None of these organs contain an atrium as a structural component. This distinction highlights the specific role and location of the atrium within the heart's anatomy.