fonalitÃ© | Flickr. American Express uses the first two numbers of the card to identify itself. That two-digit number will be either 34 or 37. The third and fourth digit signify the type of card and the currency being used, according to Clearpoint Credit Counseling.
Formed Elements of the Blood. the solid fraction of the blood, consisting of erythrocytes, leukocytes, and thrombocytes. The formed elements constitute up to 40 percent of the volume of the blood in lower vertebrates (fishes, amphibians, and reptiles) and up to 54 percent in higher vertebrates (birds and mammals, including man). The most numerous among the formed elements of the blood are the erythrocytes, which contain hemoglobin. They transfer oxygen from the respiratory organs to the tissues and help transfer carbon dioxide in the opposite direction.
Whole blood is composed of plasma (fluid portion of blood) and formed elements (blood cells and platelets). Plasma is the fluid portion of blood that contains proteins, ions, nutrients, hormones, antibodies, metabolites, enzymes, clotting factors, etc. Plasma is straw-colored and makes up approximately 55% of whole blood volume.