7～9 μm 6～8 μm The smallest vessels in the body, about 7～9 μm. The most thin vessels, about 0.2~0.4μm thick, one layer of endothelial cell
CapillariesDistribution -----very wideThe total length is ----- very longThe diameter is ---- very smallThe wall of capillary is ----- very thinFunction:interchange substances betweenblood and tissues
Capillaries Distribution -very wide The total length is- very long The diameter is - very small The wall of capillary is- very thin Function: interchange substances between blood and tissues
&Structure:l.Alayerofendothelialcells/endotheliumFigure 11-1.Diagram to illustrate the arrangement of endothelial cells comprising the wall of a capillarv.The boundaries of the endothelial cells may be outlined by silver impregnation
Structure： 1. A layer of endothelial cells/ endothelium
2.basallamina/basementmembrane皮细胞dothelial cell
2.basal lamina/ basement membrane
3.pericytes:/flattenedwithprocesses/ofmesenchymalorigin/contractilefunctionp
3. pericytes: /flattened with processes /of mesenchymal origin /contractile function endothelium pericyte