Neutrophils are a type of white blood cell (WBC or granulocyte) that protect us from infections, among other functions. They make up approximately 40 percent to 60 percent of the white blood cells in our bodies, and are the first cells to arrive on the scene when we experience a bacterial infection.

Monocytes are the biggest type of white blood cell in the immune system. Originally formed in the bone marrow, they are released into our blood and tissues. When certain germs enter the body, they quickly rush to the site for attack.

INFLAMMATION

The inflammatory response (inflammation) occurs when tissues are injured by bacteria, trauma, toxins, heat, or any other cause. The damaged cells release chemicals including histamine, bradykinin, and prostaglandins. These chemicals cause blood vessels to leak fluid into the tissues, causing swelling. This helps isolate the foreign substance from further contact with body tissues.

The chemicals also attract white blood cells called phagocytes that "eat" germs and dead or damaged cells. This process is called phagocytosis. Phagocytes eventually die. Pus is formed from a collection of dead tissue, dead bacteria, and live and dead phagocytes.

Mast cells are long-lived tissue-resident cells with an important role in many inflammatory settings including host defence to parasitic infection and in allergic reactions. Mast cells are located at the boundaries between tissues and the external environment, for example, at mucosal surfaces of the gut and lungs, in the skin and around blood vessels. Mast cells are key players in the inflammatory response as they can be activated to release a wide variety of inflammatory mediators, by many different antigens including allergens, pathogens and physiological mediators.

Interferons (IFNs) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten their anti-viral defenses

A fever is a prevention technique for the body to prevent the bacteria from replicating

Antigen - a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.

The basic structural unit of an antibody molecule consists of four polypeptide chains

The basic structural unit of an antibody molecule consists of three polypeptide chains

Immunoglobulins, also known as antibodies, are glycoprotein molecules produced by plasma cells (white blood cells). They act as a critical part of the immune response by specifically recognizing and binding to particular antigens, such as bacteria or viruses, and aiding in their destruction.

The various antibodies produced by plasma cells are classified by isotype.

The various antibodies produced by plasma cells are classified by protein type.

Five major antibody classes have been identified in placental mammals: IgA, IgD, IgE, IgG and IgM.

Passive immunity is an immune response which involves antibodies obtained from outside the body. An example of this is the antibodies a mother passes to her infant through her breastmilk.

Naturally acquired passive immunity – IgG through the plasma during pregnancy.