In comparing the pressures within the heart, how does the right atrium pressure compare to the left atrium pressure?

In a healthy heart, the pressure in the right atrium is significantly lower than that in the left atrium. This difference is primarily due to the distinct roles and functions of each side of the heart.

The right atrium receives deoxygenated blood from the body through the superior and inferior vena cavae and pumps it into the right ventricle. This process does not require high pressure because it is assisted by the relatively low pressure in the venous system. Consequently, the right atrium's average pressure is typically around 0 to 5 mmHg.

In contrast, the left atrium receives oxygenated blood from the lungs through the pulmonary veins and needs to generate a bit more pressure to effectively push this blood into the left ventricle. This pressure in the left atrium is generally higher, averaging around 5 to 10 mmHg.

The difference in pressures between the two atria is essential for efficient blood flow through the heart and into the systemic and pulmonary circuits. Understanding this critical pressure comparison is key for BMET professionals when assessing cardiac function and diagnosing potential issues.