Blood Flow in the Valves of Veins Small 320×219 Medium 640×438 Large 1024×700 Download Tiff Original 2400×1641 | (3.5 MB) Description A, vein with valves open. B, vein with valves closed: stream of blood passing off by lateral channel. Keywords lateral channel, valve, vein Galleries Human Systemic Circulation Source: Baker, W. Morrant & Harris, Vincent Dormer Kirkes' Hand-book of Physiology, 13th ed. (Philadelphia: P. Blakiston's Son & Co., 1892) 187