fenestrado

Fenestrado is an adjective used in Portuguese and Spanish to indicate that a structure has fenestrae—small openings or windows in its surface. In English, the corresponding term is fenestrated. The word derives from Latin fenestra, meaning “window.” In biology and medicine, fenestration describes a tissue architecture that allows rapid exchange of substances between compartments.

In architecture, being fenestrado refers to a building or wall that includes a defined arrangement of window openings. Fenestration affects light, ventilation, acoustics, and the visual character of the facade.

In histology and physiology, fenestrated endothelium describes capillaries with pores, or fenestrae, in the endothelial layer. These fenestrae, typically about tens of nanometers in diameter, permit passage of small molecules between blood and surrounding tissue. Some fenestrae are covered by thin diaphragms that modulate permeability. Fenestrated capillaries are found in organs where rapid exchange is essential, such as the kidneys (glomerular capillaries), endocrine glands, the intestinal mucosa, and the choroid plexus.

Compared with continuous capillaries, fenestrated capillaries are more permeable due to the presence of pores; compared with sinusoidal capillaries, they have smaller openings and higher selectivity. Fenestration can be influenced by physiological conditions and certain disease states, affecting filtration and absorption at the tissue level.