File Name: immune system parts and functions .zip
Immune system , the complex group of defense responses found in humans and other advanced vertebrates that helps repel disease-causing organisms pathogens. Immunity from disease is actually conferred by two cooperative defense systems, called nonspecific, innate immunity and specific, acquired immunity. Nonspecific protective mechanisms repel all microorganisms equally, while the specific immune responses are tailored to particular types of invaders. Both systems work together to thwart organisms from entering and proliferating within the body. These immune mechanisms also help eliminate abnormal cells of the body that can develop into cancer.
The immune system is the body's defense against infections. Many cells and organs work together to protect the body. Some types of white blood cells, called phagocytes FAH-guh-sytes , chew up invading organisms. Others, called lymphocytes LIM-fuh-sytes , help the body remember the invaders and destroy them. When someone might have bacterial infection, doctors can order a blood test to see if it caused the body to have lots of neutrophils. Other types of phagocytes do their own jobs to make sure that the body responds to invaders.
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 go to the thymus gland to mature into T cells. B lymphocytes are like the body's military intelligence system — they find their targets and send defenses to lock onto them. T cells are like the soldiers — they destroy the invaders that the intelligence system finds.
When the body senses foreign substances called antigens , the immune system works to recognize the antigens and get rid of them. B lymphocytes are triggered to make antibodies also called immunoglobulins. These proteins lock onto specific antigens. After they're made, antibodies usually stay in our bodies in case we have to fight the same germ again.
That's why someone who gets sick with a disease, like chickenpox, usually won't get sick from it again. This is also how immunizations vaccines prevent some diseases. An immunization introduces the body to an antigen in a way that doesn't make someone sick. But it does let the body make antibodies that will protect the person from future attack by the germ. Although antibodies can recognize an antigen and lock onto it, they can't destroy it without help.
That's the job of the T cells. They destroy antigens tagged by antibodies or cells that are infected or somehow changed. Some T cells are actually called "killer cells. These specialized cells and parts of the immune system offer the body protection against disease.
This protection is called immunity. The immune system takes a while to develop and needs help from vaccines. By getting all your child's recommended vaccines on time, you can help keep your child as healthy as possible. Reviewed by: Larissa Hirsch, MD. Larger text size Large text size Regular text size.
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens , from viruses to parasitic worms , as well as cancer cells and objects such as wood splinters , distinguishing them from the organism's own healthy tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use molecules and cells to perform their functions. Nearly all organisms have some kind of immune system.
Victorian government portal for older people, with information about government and community services and programs. Type a minimum of three characters then press UP or DOWN on the keyboard to navigate the autocompleted search results. The immune system keeps a record of every microbe it has ever defeated, in types of white blood cells B- and T-lymphocytes known as memory cells. This means it can recognise and destroy the microbe quickly if it enters the body again, before it can multiply and make you feel sick.
Our immune system is essential for our survival. Without an immune system, our bodies would be open to attack from bacteria, viruses, parasites, and more. It is our immune system that keeps us healthy as we drift through a sea of pathogens. This vast network of cells and tissues is constantly on the lookout for invaders, and once an enemy is spotted, a complex attack is mounted.
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The immune system includes primary lymphoid organs, secondary lymphatic tissues and various cells in the innate and adaptive immune systems. The key primary lymphoid organs of the immune system include the thymus and bone marrow, as well as secondary lymphatic tissues including spleen, tonsils, lymph vessels, lymph nodes, adenoids, skin, and liver.
The adaptive immune system , also referred as the acquired immune system , is a subsystem of the immune system that is composed of specialized, systemic cells and processes that eliminate pathogens or prevent their growth. The acquired immune system is one of the two main immunity strategies found in vertebrates the other being the innate immune system. Like the innate system, the adaptive immune system includes both humoral immunity components and cell-mediated immunity components and destroys invading pathogens.
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