arteríolas
Arterioles are small branches of arteries that lead to capillaries. They are crucial components of the circulatory system, playing a significant role in regulating blood flow and blood pressure. Their walls are composed of smooth muscle and elastic tissue, which allows them to constrict or dilate in response to various physiological signals. This ability to change their diameter is known as vasomotion, and it is fundamental to controlling the distribution of blood throughout the body. The precise control of blood flow by arterioles ensures that organs and tissues receive the oxygen and nutrients they require, while also influencing overall systemic blood pressure. When arterioles constrict, resistance to blood flow increases, leading to a rise in blood pressure. Conversely, dilation of arterioles decreases resistance and lowers blood pressure. This dynamic regulation is vital for maintaining homeostasis and responding to the body's changing metabolic demands. The transition from arterioles to capillaries represents a point where the cardiovascular system shifts from high-pressure transport to efficient nutrient and gas exchange.