The Immune System

What is the Immune System?

The immune system is an amazing combination of cells, structures and processes that help protect us against diseases and repair damage. The immune system can be broadly divided into non-specific or innate and specific or adaptive immunity.

General Grevious from Star Wars

Innate immunity is a non-specific first line of defence, comprising physical barriers, such as the skin, traps, such as the mucous lining of the nose and throat, chemical defences, such as the low pH of the stomach and a range of cells including macrophages and neutrophils. The innate response is the same no matter what threat it encounters and is present from birth, primed and ready to protect us for the initial challenges of an infection. Sometimes the innate system is able to destroy the threat on its own, in other cases it can become overwhelmed and a second, more specific system kicks in.

Darth Maul from Star Wars

The adaptive immune system is the second line of defence which mounts a response that is highly specific to the threat being encountered. To do this the adaptive immune response builds up immune memory of previously encountered threats, which allows for a specific and robust response to the individual target. Adaptive immunity is made up of soluble components including antibodies, which normally target pathogens that have not entered a cell and are free in the blood, and cells called T-lymphocytes, which can either directly kill infected and damaged cells or help direct other components of the immune response.

The combination of these two systems working together is incredibly effective at protecting us from harmful pathogens that would otherwise cause illness or disease.



Soluble Mediators