2 BALANCE YOUR IMMUNE SYSTEM 2 BALANCE YOUR IMMUNE SYSTEM Macrophage Chapter One Meet Your Immune System Your immune system is an intricate network made up of specialized tissues, organs, cells, and chemicals that work in concert to keep you healthy. This complex system is designed to actively identify and neutralize foreign substances known as “antigens”—including harmful viruses, bacteria, and environmental contaminants—before they can make you ill. A healthy immune system also patrols your body for damaged cells that might morph into cancerous cells and tries to eradicate them. Ready Response Accomplishing this search and destroy mission requires 24/7 vigilance.This is why the immune system is made up of two parts: the innate and acquired immune responses.The innate system is the body’s first line of defense against foreign substances that may lead to disease. It includes physical barriers to infection like the skin or the mucous membranes and chemical barriers like the acidic environment in your gut or the specialized enzymes that kill off bacterial or viral cells.The complement system, which is a group of serum proteins, is also an important part of innate immunity. It can kill pathogens directly or mark them for later destruction by certain immune cells called phagocytes. The adaptive (acquired) response is a delayed immune response that is dependent on the innate system for activation. Although its response is initially delayed, the adaptive system has the unique ability to remember a bacterium or virus that you’ve been exposed to in the past. When it encounters the same pathogen again, it responds quickly to neutralize the threat. The main cells in the adaptive response are B-cells and T-cells. One type of T-cell is known as the T-helper (Th) cell. These unique warrior cells can quickly recognize and destroy virus-infected cells. Th-cells also activate other immune Cellular Superheroes A massive militia of white blood cells known as phagocytes and lymphocytes are among the most important components of a healthy immune system. Some phagocytes, called macrophages, constantly patrol your body, destroying germs as soon as they enter. Macrophages also produce Tumor Necrosis Factor (TNF) that kills some types of tumor cells, manages inflammation, and triggers the creation of new blood cells. If an infection begins to take hold, your body fights back with even more powerful T-cells and B-cells. B-cells identify harmful bacteria and also remember certain pathogens so that the same germ can be identified and hopefully fought off the next time you come in contact with it.T-cells, including T-helper cells, are the foot soldiers that destroy the bad actors that the B-cells have identified. One specialized type of T-cell is the powerful Natural Killer (NK) cell that can eradicate certain tumour cells and virus-infected cells. powerful Natural Killer (NK) cell that can eradicate certain tumour cells and virus-infected cells. T-Cell B-Cell Natural Killer Cell