31. Another possible explanation is that there is an increase in local venous blood volume . 32. Blood volume increases act to increase stroke volume of the heart via Starling's law.33. The red cells would have been possible, but that would not change the blood volume . 34. In space, astronauts lose fluid volume including up to 22 % of their blood volume . 35. Horses are used because of the large blood volume . 36. Such factors include low blood volume , diseases, and medications. 37. "That is equal to or less than 10 percent of the average person's blood volume . 38. Reabsorption of sodium results in retention of water, which increases blood pressure and blood volume . 39. That's because blood substitutes do not expand blood volume . 40. The principal buffers for increased volumes include CSF and, to a lesser extent, blood volume .