Fenestra (histology)

Scanning electron micrograph of a liver sinusoid with fenestrated endothelial cells. Fenestræ are approx 100 nm in diameter, with a sinusoidal width of 5 micrometres. Magnification 30,000X

In histology, fenestræ are small pores in endothelial cells that allow for rapid exchange of molecules between fenestrated blood vessels, sinusoid blood vessels and surrounding tissue. These pores may enlarge and contract at the action of various stimuli such as noradrenaline. Fenestræ (singular: fenestra) is a Latin word that means "window".

Index of the circulatory system

Description	Anatomy Arteries head and neck arms chest abdomen legs Veins head and neck arms chest abdomen and pelvis legs Development Cells Physiology proteins

Disease	Congenital Neoplasms and cancer Lymphatic vessels Injury Vasculitis Other Symptoms and signs eponymous

Treatment	Procedures Drugs beta blockers channel blockers diuretics nonsympatholytic vasodilatory antihypertensives peripheral vasodilators renin–angiotensin system sympatholytic antihypertensives vasoprotectives

Fenestra (histology)

See also