The resistance of the arterioles accounts for what percentage of the total systemic resistance?

The resistance offered by the arterioles is significant because they are the primary sites for the regulation of blood flow and blood pressure in the systemic circulation. In the systemic vascular system, arterioles play a crucial role in controlling vascular resistance due to their ability to constrict and dilate.

Arterioles, despite being a small portion of the entire vascular tree, account for a major proportion of total systemic resistance, which is around 30%. This is because they provide the greatest resistance to blood flow, thus determining a large part of the systemic vascular resistance experienced by the heart. By controlling the diameter of these vessels, the body can efficiently regulate blood flow and blood pressure according to demand.

On the other hand, larger vessels such as arteries contribute significantly to blood flow but have less resistance compared to arterioles, which is why the percentage contributed by arterioles stands out. Understanding the dynamics of resistance in the circulatory system is essential for comprehending how blood pressure and flow are managed by the body.