Aorta and major arteries branching from aortic arch Major arteries branching from abdominal aorta See the aorta and its major branches. Capillaries join arterial blood flow to venous blood flow. Veins carry blood from organs to atria of heart. Lymphocytes produce molecules that recognize antigens and bind to them. When stimulated by antigen lymphocytes produce clones of immunity cells and memory cells.
Antigens are proteins foreign to the body.
B-lymphocytes secret antigen specific antibodies. are responsible for humoral immunity.