ANSC 3080 Lecture Notes - Lecture 9: Extracellular Fluid, Smooth Muscle Tissue, Endothelium
18 Oct 2016
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Document Summary
Site of water-nutrients-wastes-gases exchanges w. interstitial fluid and tissues. 7-8 um diameter, 0. 5 mm in length (rbcs ~7. 5 um in diameter) = 1 rbc can travel through at a time. Dense networks each cell of a tissue w. in 100um of a capillary. Receive blood from smallest arterioles also from metarterioles = connection btw arteriole and capillaries network. Dense capillaries vary depending on the metabolic activity in the tissue. Metarterioles possess rings of smooth muscle tissue that can open and close on demand in skeletal muscle: all open during exercising. Resistance reduced by the extent of the parallel ramifications. Diffusion = depends on capillary type and substance properties follows gradient btw blood and interstitial fluid. Lipid soluble substances exchange freely across cell membrane (o2 and co2) Most capillaries have pores or clefts that allow transfer of water and lipid-insoluble molecules. Size and number of pores depend on the tissue.
