Coloured scanning electron micrograph (SEM) of an elastic artery cross-section. The cross-section was taken from a small elastic artery originally from a human lung. The lumen contains red blood cells (red) and platelets (yellow). In the wall of the blood vessel, a clear internal elastic lamina (pale purple) is visible. This elastic lamina gives rise to the Windkessel effect, which helps to maintain a relatively constant pressure in the arteries despite the pulsating nature of the blood flow.
Image Source: Science Photo Library.