Capillary, illustration 插畫檔

Illustration showing the cross-sectional structures of three primary capillary types arranged vertically. The upper section shows continuous capillaries characterized by tightly joined endothelial cells and an intact basement membrane, typically located in muscular and nervous tissues to maintain barrier integrity. The middle section illustrates fenestrated capillaries featuring endothelial fenestrations that facilitate the rapid passage of small molecules, predominantly found in renal glomeruli and endocrine glands. The lower section presents sinusoidal capillaries with wide, irregular lumens, large intercellular gaps, and a discontinuous basement membrane, commonly observed in the liver, spleen, and bone marrow to permit the transit of large macromolecules and blood cells