Print. An orthopedic surgeon, or orthopaedic surgeon, is a surgeon who has been educated and trained in the diagnosis and preoperative, operative, and postoperative treatment of diseases and injuries of the musculoskeletal system. Orthopedic surgeons work closely with other health care providers and often serve as consultants to other physicians.
Reviewed October 2008. The immune system is composed of many interdependent cell types that collectively protect the body from bacterial, parasitic, fungal, viral infections and from the growth of tumor cells. Many of these cell types have specialized functions. The cells of the immune system can engulf bacteria, kill parasites or tumor cells, or kill viral-infected cells.
The immune system is very complex. It's made up of several types of cells and proteins that have different jobs to do in fighting foreign invaders. In this section, we'll take a look at the parts of the immune system in some detail.