Capillary

<p>A capillary is a small <a href="/facts/Blood_vessel/FG3GjPNW">blood vessel</a>, from 5 to 10 <a href="/facts/Micrometre/7eDFxD2L">micrometres</a> in diameter, and is part of the <a href="/facts/Microcirculation/EecoBYyz">microcirculation</a> system. Capillaries are microvessels and the smallest blood vessels in the body. They are composed of only the <a href="/facts/Tunica_intima/x8gCjsuG">tunica intima</a> (the innermost layer of an artery or vein), consisting of a thin wall of simple squamous <a href="/facts/Endothelial_cell/L4ENFVnw">endothelial cells</a>. They are the site of the exchange of many substances from the surrounding <a href="/facts/Interstitial_fluid/hzm4qatP">interstitial fluid</a>, and they convey blood from the smallest branches of the arteries (<a href="/facts/Arteriole/HYVG0g7P">arterioles</a>) to those of the veins (<a href="/facts/Venule/L4uIvXuo">venules</a>). Other substances which cross capillaries include water, <a href="/facts/Oxygen/acyn6o8r">oxygen</a>, <a href="/facts/Carbon_dioxide/xGzpppEp">carbon dioxide</a>, <a href="/facts/Urea/6j84AoCG">urea</a>, <a href="/facts/Glucose/oUSkoLCD">glucose</a>, <a href="/facts/Uric_acid/gPMSfLcT">uric acid</a>, <a href="/facts/Lactic_acid/BsVRFx7s">lactic acid</a> and <a href="/facts/Creatinine/gkebqj2L">creatinine</a>. <a href="/facts/Lymph_capillaries/eYeHIbeI">Lymph capillaries</a> connect with larger <a href="/facts/Lymph_vessel/jND0hlDu">lymph vessels</a> to drain <a href="/facts/Lymph/SL1xvRhq">lymphatic</a> fluid collected in microcirculation.
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Capillary open-in-new

Capillary