Functions of blood

Composition of blood

Plasma - 55%

Formed elements (blood cells) - 45%

Blood cells

Erythrocytes (Red blood cells)

cytoplasm contains hemoglobin

flattened, no nucleus, mitochondria or ribosomes

transport oxygen and carbon dioxide

Leukocytes (White blood cells)

Neutrophils (57%)

engulf pathogens and debris

Eosinophils (2.4%)

engulfs antibody bound pathogens

Basophils (0.6%)

release histamine

Monocytes (6.5%)

engulf pathogens and debris

enter tissues to become macrophages

Lymphocytes - small (28%)

B-lymphocytes form antibodies

T-lymphocytes attack viruses and invaded cells

Lymphocytes - large (3%)

NK-lymphocytes attack damaged or foreign cells


clump together, activate coagulation


David G. Ward, Ph.D.  Last modified by wardd 23 May, 2006