The cells that perform immunological surveillance are known as sentinel or surveillance cells. These are specialized cells that are responsible for monitoring the immune system for any abnormal or potentially dangerous foreign bodies, such as viruses, bacteria, and other pathogens. Once they detect a potential threat they will alert the body’s other cells so that they can fight against the invader.

Sentinel or surveillance cells are found in many locations throughout the body, including the lymph nodes, spleen, thymus, and mucosal surfaces. In the immune system, these cells act as the “first line of defense” by identifying foreign invaders before they can cause any major harm. Sentinel cells can also alert the body to the presence of any other abnormal cells, such as cancer cells.

The main type of sentinel or surveillance cells are a type of white blood cell known as a macrophage. Macrophages are large cells that are able to swallow up and digest foreign particles. When a macrophage detects a foreign invader, it will release signals to alert the other immune cells that an attack is occurring.

Other important types of sentinel cells include natural killer cells, neutrophils, and dendritic cells. Natural killer cells are able to recognize and destroy abnormal cells and cells infected with viruses. Neutrophils are specialized cells that are able to engulf and destroy bacteria and other pathogens. Lastly, dendritic cells are important for their ability to process and present antigens to other cells of the immune system, as well as for their ability to initiate an immune response against foreign invaders.

Overall, sentinel or surveillance cells are an essential part of the immune system. By constantly monitoring for foreign invaders and other abnormal cells, these specialized cells help protect the body from disease and illness.