Cytoxic T-cells

attack foreign cells or body cells infected by viruses


differentiate into plasma cells which produce antibodies

Natural Killer (NK) cells

attack foreign cells, normal cells infected with viruses, or cancer cells appearing in normal tissue

Lymphatic tissues and organs

connective tissues dominated by lymphocytes

Lymph nodes - contain macrophages and lymphocytes acting on lymph

Thymus - site for maturation of T-cells

Spleen - contains macrophages and lymphocytes acting on blood

Nonspecific defenses


Specific defenses (Immunity)

Cellular immunity

direct attack by cytotoxic T-cells

Humoral immunity

attack by circulating antibodies

Antibodies bind to antigen and

Functions of the lymphatic system

Lymphatic vessels

Lymphatic capillaries

Lymphatics ducts

ducts empty into the venous system at the junction of the internal jugular vein and and the subclavian vein on the corresponding side


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