Red blood cell the centre of 0.8–1 µm, being much smaller than most other human cells. These cells have an average volume of about 90 fL with a surface of about 136 μm, and can swell up to a sphere shape containing 150 fL, without membrane distension. Adult humans have roughly 20–30 trillion red blood cells at any given time, constituting approximately 70% of all cells by number. Women have about 4–5 million red blood cells per microliter (cubic millimeter) of blood and men about 5–6 million; people living at high altitudes with low oxygen tension will have more. Red blood cells are
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