Red blood cell being dissolved in body fluid) was an important step in the evolution of vertebrates as it allows for less viscous blood, higher concentrations of oxygen, and better diffusion of oxygen from the blood to the tissues. The size of red blood cells varies widely among vertebrate species; red blood cell width is on average about 25% larger than capillary diameter, and it has been hypothesized that this improves the oxygen transfer from red blood cells to tissues. The red blood cells of mammals are typically shaped as biconcave disks: flattened and depressed in the center, with a dumbbell-shaped cross section,
Blood Red Horse Blood Red Horse Blood Red Horse is a 2004 young adult historical novel by author K M Grant. The book was published in 2004 by Puffin Books and in the US in 2005 by Walker Children's. "Blood Red Horse" is the first novel in the De Granville Trilogy and was followed by the books "Green Jasper" and "Blaze of Silver". In 2006 the audiobook version of "Blood Red Horse" won an AudioFile Earphones Award and in 2007 was one of YALSA's recommended audiobooks for 2007. "Blood Red Horse" follows Will and Ellie, two young teens growing up during the time