ABSTRACT
Blood is a viscous ¢uid mixture consisting of plasma and cells. Table 4.1 summarizes the most important physical properties of blood. Recall that the chemical composition of plasma was previously shown in Table 3.2. Proteins represent about 7-8 wt% of plasma. The major proteins found in plasma are albumin (MW = 69,000; 4.5 g 100 mL-1), globulins (MW = 35,000-1,000,000; 2.5 g 100 mL-1), and ˜brinogen (MW = 400,000; 0.3 g 100 mL-1). Albumin has a major role in regulating the pH and the colloid osmotic pressure. The so-called alpha and beta globulins are involved in solute transport, whereas the gamma globulins are the antibodies that ˜ght infection and form the basis of the humoral component of the immune system. Fibrinogen, through its conversion to long strands of ¢brin, has a major role in the process of blood clotting. Serum is simply the ¢uid remaining after blood is allowed to clot. For the most part, the composition of serum is the same as that of plasma, with the exception that the clotting proteins, primarily ˜brinogen, and the cells have been removed.
