Library · Cell
Venous endothelium
Make it clearer
The venous endothelium is not a separate type of cell. It is the same endothelium found everywhere else: a single layer of flat, simple squamous cells that forms the innermost lining of every vessel in the body and rests on a basal lamina, the supporting sheet that anchors it to the connective tissue underneath.
What is interesting is how it looks. In a section under the microscope, the lumen of a vein, meaning its interior space, and its whole tunica intima appear smooth. In an artery they usually appear wavy, like gathered fabric, and there is a reason for that: it is the smooth muscle of the tunica media, the muscular layer of the artery, contracting partway and puckering the lining.
And that same lining does more than just line the vessel. In many veins of the lower limbs, that is, the legs, there are stretches where the endothelium thickens and is reinforced with connective tissue, and those stretches lift up into the lumen: these are the venous valves. They are made of the vessel's own lining.
In brief
The venous endothelium is the same single layer of simple squamous endothelial cells that forms the innermost lining of any vessel, resting on a basal lamina.
Under the microscope, the lumen and the entire tunica intima of a vein look smooth, while those of an artery usually look wavy because the smooth muscle of its tunica media is partly contracted.
And in many veins of the lower limbs, thickened sections of endothelium reinforced with connective tissue form the valves that project into the lumen.
Sources (2)
- National Center for Biotechnology InformationHistology, Blood Vascular System. StatPearls
- OpenStax, Rice UniversityAnatomy and Physiology 2e, 20.1 Structure and Function of Blood Vessels
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated