Which statement about capillaries is FALSE?

Capillaries are the smallest blood vessels in the circulatory system, and their structure is specifically adapted for their function in gas and nutrient exchange. Each capillary has a very thin wall composed primarily of a single layer of endothelial cells, which allows for efficient diffusion of substances. While the endothelial layer can be considered part of the intima, capillaries do not have a separate adventitia layer as seen in larger blood vessels. The structure of a capillary is simpler than that of arteries and veins, which indeed have intima, media, and adventitia layers. Therefore, stating that capillaries have only intima and adventitia is misleading as they fundamentally lack the media layer and the distinct adventitia found in larger vessels.

Regarding the other choices, capillaries do indeed measure approximately 8 microns in diameter, which is critical for allowing red blood cells to pass through in single file. The blood transmission time through capillaries of approximately one to three seconds is essential for effective exchange, allowing enough time for oxygen, nutrients, and waste products to diffuse across the capillary walls. The loss of fluid at the arteriolar end is a normal physiological process; capillaries are involved in the exchange of fluids and solutes,