Orthopedic surgeons receive 5 or more extra years of training after school. 1  They specialize in the care of disorders of the bones, muscles, tendons, and ligaments. They are trained to manage joint problems with both operative and non-operative techniques.
What the Immune System Does. The immune (pronounced: ih-MYOON) system, which is made up of special cells, proteins, tissues, and organs, defends people against germs and microorganisms every day. In most cases, the immune system does a great job of keeping people healthy and preventing infections.
Antibodies are large Y-shaped protein molecules created by the immune system to identify and neutralize foreign objects and pathogens, such as bacteria, viruses, fungi, parasites, and toxins. Also known as immunoglobulin, antibodies are manufactured by white blood cells called B-lymphocytes, or B-cells.