What does the term 'lumen' refer to in vascular biology?

The term 'lumen' in vascular biology pertains to the central cavity of a blood vessel. This is the space within the vessel through which blood flows. The lumen plays a critical role in vascular function, as its diameter can influence blood flow and pressure. The integrity and size of the lumen are important for efficient circulation, as any obstruction or narrowing can lead to various cardiovascular issues.

Understanding the structure and function of the lumen is essential for comprehending how blood vessels operate, including how they respond to different physiological stimuli, such as changes in blood flow or pressure.