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.
Your blood is made of white blood cells, red blood cells,  platelets, and plasma.   The white blood cells fight infections and are part of the body's  immune system.aguely speaking, human blood is composed of blood cells, plasma, and platelets More specifically, Human blood has about 45% blood cells and 55 percent plasma. The blood cel â¦ ls contain erythrocytes(red blood cells) and leukocytes(white blood cells), but it's mostly red blood cells.