Final answer:
Arterioles are small arteries that do not have individual names because of their extensive branching and small size. They are known as distributing arteries and differ from the closer-to-heart elastic arteries that contain more elastic fibers and have the ability to expand and recoil.
Step-by-step explanation:
The type of arteries that are usually too small to be given individual names are arterioles. Arterioles are farther from the heart, and they contribute significantly to the vascular resistance and regulation of blood pressure. They have smaller diameters, ranging from about 0.1 mm to 10 mm, and are known as distributing arteries because they branch off from muscular arteries and distribute blood to various parts of the body. Due to the extensive branching and their smaller size, they generally do not have individual names like the larger elastic and muscular arteries do.
Elastic arteries are closest to the heart and have the ability to expand and recoil due to their high percentage of elastic fibers, which helps to maintain blood pressure and flow throughout the arterial system. Muscular arteries have a thick tunica media allowing them to regulate blood flow by vasoconstriction. The vasa vasorum primarily nourishes the outer layers of arteries, making them less prone to diseases than veins. The nervi vasorum within the walls of blood vessels controls the contraction and dilation of the smooth muscle.