Immune System

The four types of pathogens include Bacteria, viruses, fungi, and parasites.

Macrophage- A type of white blood that absorbs material that our bodies are not accustomed to. Macrophages play a vital role by responding immediately t microorganisms that are possibly infectious.

Antigen- foreign microorganisms that the body is not used to, that stimulates an immune response through activating the body’s infection-fighting white blood cells

T cell- a type of lymphocytes that protect the body through identifying, directly attacking and destroying the infectious substances found in the body. These cells activate the B cells and killer T cells.

B cell- these cells are produced in the bone marrow. They develop into plasma cells that become the source of antibodies.

Antibody- the protein that is produced by the body’s immune system whose function is to detect and respond to antigen.

Killer cell- type of cell that is able to kill off cancerous cells or virus-infected cells.

cytotoxic T cell- The cytotoxic T-cells fit as a sub-category of the t-cells. However, it is distinguished from the other t-cells because of its CD8 receptor. These cells are able to detect antigens on the surface of a virus-infected cell. As soon as it spots an infectious cell, the T-cells bind itself to the infected cell and kill it.

Memory cell- These cells are capable of remembering specific intruders. Therefore, as soon as an intruder tries to invade the body for the second time, B and T memory cells help the immune system to activate much faster. The invaders are wiped out before the infected human feels any symptoms.

We are born with Passive immunity. The mother’s immunity is passed down to the newborn in order to protect the baby from infection. The passive immunity stays as the time needed for the body to develop its own immune response. Another form of immunity that we are born with, is called innate immunity. It protects and prevents all of the external diseases from entering into our bodies. However, the adaptive immunity is the immunity where the memory cells kick in. As our bodies are exposed to various different antigen, our adaptive immunity is continuously built.

Selective IgA Deficiency : Selective IgA Deficiency is the most common of the primary Immunodeficiencies. People with this condition have total absence or severe deficiency of IgA because B-lymphocytes  are unable to mature into IgA-producing plasma cells. IgA deficient people have B cells that are stopped at an immature stage. The IgA class of immunoglobulins has the specific function of protecting the body's mucosal surfaces (eyes, mouth, throat, lungs, gastrointestinal, and genitourinary tract) from infection. Therefore, the lack IgA at these places typically causes infection, allergies, chronic diarrhea, or autoimmune diseases. In autoimmune diseases, the immune system mistakenly attacks the body's own tissues.

Hay Fever: is also known as allergic rhinitis.  The body’s  immune system thinks that the allergen (pollen, mold, dander, etc.) as an "foreign invader" and responds by releasing a chemical called histamine into the bloodstream. This chemical, Histamine,  causes inflammation (swelling and redness) of the sinuses, nose, and mucus membranes of the eyes and triggers sneezing. The swelling reaction is designed to block the allergen from entering the body and sneezing is a method to expel it out of the body. Histamine also allows fluids to enter the nasal tissue, resulting in congestion and an itchy, runny nose.