Atrium

Definition

An atrium is one of the two upper chambers of the heart that receives blood returning from the body or lungs. It plays a crucial role in the circulation process by passing blood to the ventricles.

5 Must Know Facts For Your Next Test

1. There are two atria in the human heart: the left atrium and the right atrium.
2. The right atrium receives deoxygenated blood from the body through veins such as the superior and inferior vena cava.
3. The left atrium receives oxygenated blood from the lungs via the pulmonary veins.
4. Atrial contraction helps push blood into the ventricles, which then pump it out to either the lungs or the rest of the body.
5. Malfunctions in atrial function can lead to conditions such as atrial fibrillation, which affects heart rhythm.

Review Questions

• What is the primary function of an atrium in the heart?
• Which side of the heart's atrium receives oxygenated blood and from where?
• What type of blood does the right atrium receive and through which vessels?

Related terms

Ventricle: A lower chamber of the heart that pumps blood out to either the lungs or to other parts of the body.

Pulmonary Vein: The vein that carries oxygenated blood from the lungs to the left atrium.

Superior Vena Cava: A large vein that carries deoxygenated blood from parts of the body above the diaphragm back to the right atrium.