Blood

• Plasma makes up about 55% of the total volume of blood
• The blood is composed of plasma, red cells, white cells, platelets
• What is the buffy coat?

  The buffy coat is the layer of white blood cells and platelets that forms between the plasma and red blood cells when a blood sample is centrifuged.
• Plasma proteins (~7% of plasma): all proteins serve to buffer against pH changes
• Albumin (~58% of plasma proteins): exerts osmotic force to retain fluid, blood viscosity, binds and transports (fatty acids, electrolytes, hormones, drugs)
• Globulins (~37% of plasma proteins): transport lipids and some metal ions (α), transport iron ions and lipids (β), antibodies (γ)
• Fibrinogen (~4% of plasma proteins): blood coagulation, precursor of fibrin