The immune system is a group of cells, tissues and organs that function to recognize and destroy pathogenic bacteria and viruses. It is the body's main defense against foreign antigens and works to keep humans healthy ev... More »

The job of the immune system is to defend the body against infectious organisms and other intruders. This occurs primarily through the actions of white blood cells. Phagocytes destroy non-native cells and organisms, whil... More »

The main function of the immune system is to protect the human body against disease and other foreign bodies. The human immune system is a complex system that can identify threats to human health, distinguish these threa... More »

A group of tissues that work together to perform one basic function are called organs. When groups of organs work together to perform the same function, they are referred to as an organ system. More »

An organ is defined as a group of tissues that work together to perform a specific function. Examples of an organ include the stomach, brain and liver. More »

The immune system maintains homeostasis by preventing pathogens from disrupting the body's normal functioning. It achieves this in various ways, including adaptive immunity when the body encounters a new pathogen, innate... More »

A mechanical barrier in the immune system is a primary line of defense, which physically impedes the entry of foreign particles that may harm the body. Common mechanical barriers include the skin, mucous membranes and th... More »