The innermost layer of the vein is the tunica intima. This layer consists of flat epithelial cells. These cells allow fluid to flow smoothly and are interspersed with valves that ensure the flow continues in one direction. This continuous layer of epithelial cells holds cells and fluid within the vessel lumen.

What is the function of the tunica intima of elastic arteries?

The thin outer layer of the tunica intima contains a small amount of areolar connective tissue that consists primarily of elastic fibers to provide the vessel with additional flexibility; it also contains some collagenous fibers to provide additional strength.

What makes up tunica intima?

The tunica intima consists of a layer of endothelial cells lining the lumen of the vessel, as well as a subendothelial layer made up of mostly loose connective tissue. ... Finally, the tunica adventitia is primarily composed of loose connective tissue made up of fibroblasts and associated collagen fibers.