Now, why is that important? Well, it turns out that capillaries are specialized blood vessels where we have the exchange of nutrients and waste products taking place between the cells, the tissues, and the organs of our body. And these capillaries actually connect the tiny arterials to our tiny venue. So, capillaries are very tiny blood vessels that are one cell layer thick. They contain a single layer of endothelial cells that is responsible for absorbing and secreting the nutrients and the waste products between the lumen of the capillary and the cells, the tissues found in close proximity to those capillaries. So arterioles connect to the venues via these capillaries.