Atria

Definition

The atria are the two upper chambers of the heart that receive blood returning to the heart from the body and lungs. They play a crucial role in ensuring proper circulation and blood flow.

5 Must Know Facts For Your Next Test

1. The right atrium receives deoxygenated blood from the body through the superior and inferior vena cavae.
2. The left atrium receives oxygenated blood from the lungs through the pulmonary veins.
3. Atrial contraction helps fill the ventricles with blood before ventricular contraction occurs.
4. The atria have thinner walls compared to ventricles because they only need to pump blood a short distance to the ventricles.
5. Proper functioning of the atria is essential for maintaining efficient cardiac output and overall cardiovascular health.

Review Questions

• What type of blood does the right atrium receive, and from where?
• How does blood flow transition between atria and ventricles?
• Why do atria have thinner walls compared to ventricles?

Related terms

Ventricle: The two lower chambers of the heart responsible for pumping blood out to the body and lungs.

Pulmonary Veins: Blood vessels that carry oxygenated blood from the lungs to the left atrium.

Superior Vena Cava: A large vein that carries deoxygenated blood from the upper half of the body to the right atrium.