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1. Resembling a hair; fine; minute. 2. A c. vessel; e.g., blood c., lymph c.. SYN: vas capillare [TA], c. vessel. 3. Relating to a blood or lymphatic c. vessel. [L. capillaris, relating to hair]
- blood c. (symbol c, as a subscript) a vessel whose wall consists of endothelium and its basement membrane; its diameter, when the c. is open, is about 8 μm; with the electron microscope, fenestrated capillaries and continuous capillaries are distinguished.
- continuous c. a c. in which small vesicles (caveolae) are numerous and pores are absent.
- fenestrated c. a c., found in renal glomeruli, intestinal villi, and endocrine glands, in which ultramicroscopic pores of variable size occur; usually these are closed by a delicate diaphragm, although diaphragms are lacking in at least some renal glomerular capillaries.
- lymph c. the beginning of the lymphatic system of vessels; it is lined with a highly attenuated endothelium with poorly developed basement membrane and a lumen of variable caliber. See lacteal (2).
- sinusoidal c. SYN: sinusoid.
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1 a) resembling a hair esp. in slender elongated form
b) having a very small bore <a \capillary tube>
2) involving, held by, or resulting from surface tension
3) of or relating to capillaries or capillarity
capillary n, pl -lar·ies a capillary tube esp any of the smallest blood vessels connecting arterioles with venules and forming networks throughout the body
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n.
an extremely narrow blood vessel, approximately 5-20 µm in diameter. Capillaries form networks in most tissues; they are supplied with blood by arterioles and drained by venules. The vessel wall is only one cell thick, which enables exchange of oxygen, carbon dioxide, water, salts, etc., between the blood and the tissues.
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cap·il·lary (kapґĭ-lar″e) [L. capillaris hair-like] 1. pertaining to or resembling a hair. 2. any of the minute vessels that connect the arterioles and venules, forming a network in nearly all parts of the body. Their walls act as semipermeable membranes for the interchange of various substances, including fluids, between the blood and tissue fluid. The two principal types are continuous and fenestrated capillaries. Called also vas capillare [TA]. 3. vas lymphocapillare.
Capillary bed, showing the connection between the arterial and venous capillaries.
Medical dictionary. 2011.