The Liquid Tissue BLOOD Blood Blood performs two major functions: • Transport through the body of – – – – – – oxygen and carbon dioxide food molecules (glucose, lipids, amino acids) ions (e.g., Na+, Ca2+, HCO3−) wastes (e.g., urea) hormones heat • Defense of the body against infections and other foreign materials. All the WBCs participate in these defenses Components of Blood Liquid portion: Plasma • mostly water • carries just about everything (except O2/CO2) Cellular portion: Red Blood Cells • • • • Most numerous cellular portion of blood Have no nuclei; not “true” cells contain hemoglobin protein that carries O2 Look a little like Cheerios Cellular portion: White blood cells → Fight infections– Eat foreign, dead/dying, abnormal cells →Have nuclei → Several different types • Macrophages • Neutrophils Cellular portion: Platelets → Cell fragments → Help with clotting (making “scabs”) How many parts can you identify in this blood smear? RBC? WBC? Platelets? Plasma? Did you get ‘em all?