Capillary classification, illustration 插畫檔

Illustration comparing the cross-sectional structures of three primary capillary types arranged from left to right. The left section showing continuous capillaries characterized by tightly joined endothelial cells and an intact basement membrane, predominantly located in muscular and nervous tissues to maintain a selective barrier. The middle section illustrates fenestrated capillaries displaying distinct endothelial fenestrations and a continuous basement membrane, commonly found in the kidneys and endocrine glands to facilitate substance exchange. The right section showing sinusoidal capillaries featuring wide, irregular lumens, large endothelial gaps, and a discontinuous basement membrane, which permit the passage of macromolecules and blood cells and are primarily observed in the liver and spleen