Thermally Significant Vessels Arterial:100-500 m diameter 11 Venous: 400--800μn diameter 1。 blood collected from veins through tissue at different temp. Note: venous blood temp.is not always lower than that of the arterial blood Heat Transfer Analyses: (1)Large vessels (artery and vein): line source or sink in tissue depending on the temp.difference (2)Capillaries and arterioles<100 um,small veins <400 m treated as part of the tissue (3)thermally significant vessels convective effect of blood flow~ 1 e l Arterial: 100 Arterial: 100 Arterial: 100 Arterial: 100----500 ----500 ----500 ----500 μm diameter diameter diameter diameter l Venous: 400 Venous: 400 Venous: 400 Venous: 400----800 ----800 ----800 ----800 μm diameter diameter diameter diameter blood collected from veins through blood collected from veins through blood collected from veins through blood collected from veins through tissue at different temp. tissue at different temp. tissue at different temp. tissue at different temp. Note: venous blood temp. is not always venous blood temp. is not always venous blood temp. is not always venous blood temp. is not always lower than that of the arterial blood lower than that of the arterial blood lower than that of the arterial blood lower than that of the arterial blood Heat Transfer Analyses: Heat Transfer Analyses: Heat Transfer Analyses: Heat Transfer Analyses: (1) Large vessels (artery and vein): (1) Large vessels (artery and vein): (1) Large vessels (artery and vein): (1) Large vessels (artery and vein): line source or sink in tissue line source or sink in tissue line source or sink in tissue line source or sink in tissue depending on depending on depending on depending on the temp. difference the temp. difference the temp. difference the temp. difference (2) Capillaries and arterioles< (2) Capillaries and arterioles< (2) Capillaries and arterioles< (2) Capillaries and arterioles<100 μm, small veins <400 small veins <400 small veins <400 small veins <400 μm m m m treated as part of the tissue treated as part of the tissue treated as part of the tissue treated as part of the tissue (3) thermally significant vessels (3) thermally significant vessels (3) thermally significant vessels (3) thermally significant vessels convective effect of blood flow convective effect of blood flow convective effect of blood flow convective effect of blood flow Thermally Significant Vessels Thermally Significant Vessels Thermally Significant Vessels Thermally Significant Vessels