Fenestrated capillaries differ from continuous capillaries primarily due to:

Fenestrated capillaries are distinct from continuous capillaries mainly because they possess pores in the endothelial cells, which allows for increased permeability. These pores facilitate the rapid exchange of water, ions, and small molecules between the blood and surrounding tissues. Fenestrated capillaries are commonly found in areas of the body where a high rate of filtration or absorption is necessary, such as the kidneys, the intestines, and endocrine glands.

The presence of these pores is crucial for functions that require a more significant exchange of substances, distinguishing fenestrated capillaries from continuous capillaries, which have a continuous endothelial lining without such openings. This structural difference is integral in various physiological processes, such as filtration in the kidneys or nutrient absorption in the gastrointestinal tract.