How can you differentiate venules from arterioles?

Venules and arterioles can be differentiated based on their structure and function. Arterioles have thicker walls with more smooth muscle and elastic fibers, allowing them to regulate blood flow and pressure, while venules have thinner walls and less muscle, primarily functioning to collect deoxygenated blood from capillaries. Additionally, arterioles typically have a smaller lumen compared to venules, which are larger and more compliant to accommodate varying blood volumes. Histologically, arterioles may have a prominent internal elastic lamina, whereas venules do not.