The immune system

In most cases, the immune system does a great job of keeping people healthy and preventing infections. But sometimes problems with the immune system can lead to illness and infection. Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause disease. The immune system is made up of a network of cells, tissues, and organs that work together to protect the body.

The immune system

The immune system

In most cases, the immune system does a great job of keeping people healthy and preventing infections. But sometimes problems with the immune system can lead to illness and infection. About the Immune System The immune system is the body's defense against infectious organisms and other invaders.

Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause disease.

The immune system is made up of a network of cells, tissues, and organs that work together to protect the body. One of the important cells involved are white blood cells, also called leukocytes, which come in two basic types that combine to seek out and destroy disease-causing organisms or substances.

Leukocytes are produced or stored in many locations in the body, including the thymus, spleen, and bone marrow. For this reason, they're called the lymphoid organs. There are also clumps of lymphoid tissue throughout the body, primarily as lymph nodes, that house the leukocytes. The leukocytes circulate through the body between the organs and nodes via lymphatic vessels and blood vessels.

In this way, the immune system works in a coordinated manner to monitor the body for germs or substances that might cause problems.

The two basic types of leukocytes are: If doctors are worried about a bacterial infection, they might order a blood test to see if a patient has an increased number of neutrophils triggered by the infection.

Other types of phagocytes have their own jobs to make sure that the body responds appropriately to a specific type of invader. The two kinds of lymphocytes are B lymphocytes and T lymphocytes.

Lymphocytes start out in the bone marrow and either stay there and mature into B cells, or they leave for the thymus gland, where they mature into T cells. B lymphocytes and T lymphocytes have separate functions: B lymphocytes are like the body's military intelligence system, seeking out their targets and sending defenses to lock onto them.

T cells are like the soldiers, destroying the invaders that the intelligence system has identified. Here's how it works: These cells trigger the B lymphocytes to produce antibodies, which are specialized proteins that lock onto specific antigens.

So if someone gets sick with a certain disease, like chickenpox, that person usually won't get sick from it again.

This is also how immunizations prevent certain diseases. An immunization introduces the body to an antigen in a way that doesn't make someone sick, but does allow the body to produce antibodies that will then protect the person from future attack by the germ or substance that produces that particular disease.

Although antibodies can recognize an antigen and lock onto it, they are not capable of destroying it without help. That's the job of the T cells, which are part of the system that destroys antigens that have been tagged by antibodies or cells that have been infected or somehow changed.

Some T cells are actually called "killer cells. Antibodies also can neutralize toxins poisonous or damaging substances produced by different organisms.The immune system protects the body from possibly harmful substances by recognizing and responding to antigens.

Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria. Nonliving substances such as toxins, chemicals, drugs, and foreign particles (such as a.

The immune system consists of a large number of different types of cells and proteins that function to distinguish between normal and abnormal cellular components and between 'self' and 'non-self'. Inside your body there is an amazing protectio­n mechanism called the immune system. It is designed to defend you against millions of bacteria, microbes, viruses, toxins and parasites that would love to invade your body.

To understand the power of the immune system, all that you have to do is look. Paul Andersen explains how your body protects itself from invading viruses and bacteria.

He starts by describing the nonspecific immune responses of skin and inflammation. Jul 01,  · Every second of your life you are under attack. Bacteria, viruses, spores and more living stuff wants to enter your body and use its resources for itself.

The immune system is . Immune System How The Immune System Works. The role of the immune system is to protect the body from foreign micro-organisms such as viruses, bacteria, fungi and parasites.

Your Immune System Is Made, Not Born - Scientific American