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IMMUNE SYSTEM MADE EASY- IMMUNOLOGY INNATE AND ADAPTIVE IMMUNITY SIMPLE ANIMATIONImmune system defenses -
There are thousands of different kinds of bacteria, and they live in every conceivable read more , viruses Overview of Viral Infections A virus is composed of nucleic acid, either DNA or RNA, surrounded by a protein coat.
It requires a living cell in which to multiply. A viral infection can lead to a spectrum of symptoms from read more , and fungi Overview of Fungal Infections Fungi are living organisms, but they are not plants or animals.
All living things are divided into categories called kingdoms, and fungi have their own kingdom. Some fungi cause infections in read more. Parasites Overview of Parasitic Infections A parasite is an organism that lives on or inside another organism the host and benefits for example, by getting nutrients from the host at the host's expense.
Although this definition actually read more such as worms. Antigens are any substances that the immune system can recognize and that can thus stimulate an immune response. If antigens are perceived as dangerous for example, if they can cause disease , they can stimulate an immune response in the body.
Antigens may be contained within or on bacteria, viruses, other microorganisms, parasites, or cancer cells. Antigens may also exist on their own—for example, as food molecules or pollen. A normal immune response Plan of Action The immune system is designed to defend the body against foreign or dangerous invaders.
Such invaders include Microorganisms commonly called germs, such as bacteria, viruses, and fungi Parasites read more consists of the following:. What triggers an autoimmune disorder is not known. Symptoms vary depending read more , such as rheumatoid arthritis Rheumatoid Arthritis RA Rheumatoid arthritis is an inflammatory arthritis in which joints, usually including those of the hands and feet, are inflamed, resulting in swelling, pain, and often destruction of joints read more , Hashimoto thyroiditis Hashimoto Thyroiditis Hashimoto thyroiditis is chronic, autoimmune inflammation of the thyroid gland.
Hashimoto thyroiditis results when antibodies in the body attacks the cells of the thyroid gland—an autoimmune read more , or systemic lupus erythematosus Systemic Lupus Erythematosus SLE Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls.
Problems in the read more lupus. The body generates an immune response against itself an autoimmune disorder Autoimmune Disorders An autoimmune disorder is a malfunction of the body's immune system that causes the body to attack its own tissues.
The body cannot generate appropriate immune responses against invading microorganisms an immunodeficiency disorder Overview of Immunodeficiency Disorders Immunodeficiency disorders involve malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual.
The body generates an excessive immune response to often harmless foreign antigens and damages normal tissues an allergic reaction Overview of Allergic Reactions Allergic reactions hypersensitivity reactions are inappropriate responses of the immune system to a normally harmless substance.
Usually, allergies cause sneezing, watery and itchy eyes, a Antibodies Antibodies One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more immunoglobulins are proteins that are produced by white blood cells called B cells B cells One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more and that tightly bind to the antigen of an invader, tagging the invader for attack or directly neutralizing it.
The body produces thousands of different antibodies. Each antibody is specific to a given antigen. Antigens Innate Immunity are any substance that the immune system can recognize and that can thus stimulate an immune response.
B cells B cells One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more B lymphocytes are white blood cells that produce antibodies specific to the antigen that stimulated their production.
Basophils Basophils One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more are white blood cells that release histamine a substance involved in allergic reactions and that produce substances to attract other white blood cells neutrophils and eosinophils to a trouble spot.
Cells are the smallest unit of a living organism, composed of a nucleus and cytoplasm surrounded by a membrane. Chemotaxis is the process of by which a chemical substance attracts cells to a particular site.
The complement system Complement System One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more consists of a group of proteins that are involved in a series of reactions called the complement cascade designed to defend the body—for example, by killing bacteria and other foreign cells, making foreign cells easier for macrophages to identify and ingest, and attracting macrophages and neutrophils to a trouble spot.
Cytokines Cytokines One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and Dendritic cells Dendritic Cells One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more are derived from white blood cells.
They reside in tissues and help T cells recognize foreign antigens. Eosinophils Eosinophils One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more are white blood cells that kill bacteria and other foreign cells too big to ingest, and they may help immobilize and kill parasites and help destroy cancer cells.
Eosinophils also participate in allergic reactions. Helper T cells are white blood cells that help B cells produce antibodies against foreign antigens, help killer T cells become active, and stimulate macrophages, enabling them to ingest infected or abnormal cells more efficiently.
Histocompatibility literally, compatibility of tissue is determined by human leukocyte antigens self-identification molecules. Histocompatibility is used to determine whether a transplanted tissue or organ will be accepted by the recipient.
Human leukocyte antigens HLA are a group of identification molecules located on the surface of all cells in a combination that is almost unique for each person, thereby enabling the body to distinguish self from nonself.
This group of identification molecules is also called the major histocompatibility complex. Interleukin is a type of messenger cytokine secreted by some white blood cells to affect other white blood cells.
Killer cytotoxic T cells are T cells that attach to infected cells and cancer cells and kill them. Leukocyte is another name for a white blood cell, such as a monocyte, a neutrophil, an eosinophil, a basophil, or a lymphocyte a B cell or T cell.
The lymphatic system Lymphatic System: Helping Defend Against Infection is a network of lymph nodes connected by lymphatic vessels that helps the body transport microorganisms and dead or damaged cells to be filtered out and destroyed.
Acquired immune responses are initiated in the lymph nodes. Lymphocytes Lymphocytes One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more are the white blood cells responsible for acquired specific immunity, including producing antibodies by B cells , distinguishing self from nonself by T cells , and killing infected cells and cancer cells by killer T cells.
Macrophages Monocytes and Macrophages One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more are large cells that develop from white blood cells called monocytes.
They ingest bacteria and other foreign cells and help T cells identify microorganisms and other foreign substances. Macrophages are normally present in the lungs, skin, liver, and other tissues.
Mast cells are cells in tissues that release histamine and other substances involved in inflammatory and allergic reactions.
Natural killer cells are a type of white blood cell that can recognize and kill abnormal cells, such as certain infected cells and cancer cells, without having to first learn that the cells are abnormal. Neutrophils Neutrophils One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more are white blood cells that ingest and kill bacteria and other foreign cells.
Phagocytes are a type of cell that ingests and kills or destroys invading microorganisms, other cells, and cell fragments. Phagocytes include neutrophils and macrophages. Phagocytosis is the process of a cell engulfing and ingesting an invading microorganism, another cell, or a cell fragment.
T cells T cells One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and read more T lymphocytes are white blood cells that are involved in acquired immunity.
The digestive enzymes begin to break down the microbe. The phagocyte uses any nutrients it can and leaves the rest as indigestible material and antigenic fragments within the vesicle. The phagocyte makes protein markers, and they enter the vesicle.
The indigestible material is removed by exocytosis. The antigenic fragments bind to the protein marker and are displayed on the plasma membrane surface. The macrophage then secretes interleukin-1 which activates the T cells to secrete interleukin 2, as described below under specific resistance.
Inflammation is a localized tissue response that occurs when your tissues are damaged and in response to other stimuli. Inflammation brings more white blood cells to the site where the microbes have invaded. The inflammatory response produces swelling, redness, heat, pain Fever inhibits bacterial growth and increases the rate of tissue repair during an infection.
Specific Resistance Acquired Immunity The third line of defense is specific resistance. Here are the steps in an immune response: When an antigen is detected by a macrophage as describe above under phagocytosis , this causes the T-cells to become activated.
The T-cells secrete interleukin 2. Interleukin 2 causes the proliferation of certain cytotoxic T cells and B cells. From here, the immune response follows 2 paths: one path uses cytotoxic T cells and the other uses B cells. Cytotoxic T Cell Pathway The cytotoxic T cells are capable of recognizing antigens on the surface of infected body cells.
The cytotoxic T cells bind to the infected cells and secrete cytotoxins that induce apoptosis cell suicide in the infected cell and perforins that cause perforations in the infected cells.
Both of these mechanisms destroys the pathogen in the infected body cell. Activation of a helper T cell and its roles in immunity: T Cell Pathway T-cells can either directly destroy the microbes or use chemical secretions to destroy them.
At the same time, T cells stimulate B cells to divide, forming plasma cells that are able to produce antibodies and memory B cells. If the same antigen enters the body later, the memory B cells divide to make more plasma cells and memory cells that can protect against future attacks by the same antigen.
When the T cells activate stimulate the B cells to divide into plasma cells, this is called antibody-mediated immunity. Antibodies Antibodies also called immunoglobulins or Ig's are Y-shaped proteins that circulate through the blood stream and bind to specific antigens, thereby attacking microbes.
The antibodies are transported through the blood and the lymph to the pathogen invasion site. The body contains millions of different B cells, each able to respond to one specific antigen.
There are 4 classes of antibodies listed from most common to least common : IgG IgM IgA IgE IgD Each antibody is made of four polypeptide protein chains: 2 heavy chains and 2 light chains. Antibodies work in different ways: 1.
Neutralizing an Antigen The antibody can bind to an antigen, forming an antigen-antibody complex. Activating Complement: Complement is a group of plasma proteins made by the liver that normally are inactive in the body.
Precipitating Antigens Sometimes the antibodies can bind to the same free antigen to cross-link them. Adaptive Immune Response Inflammation Adaptive Immunity — Humoral and Cellular Immunity Activated vs. Anergic Immune Functionality References Assessment Questions.
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Immune System Functions Physical Immue Chemical Barriers Innate Immunity Nonspecific Energy-enhancing tips for wellness Innate Immunity Immube Resistance Immune system defenses Immunity Antibodies Types of T cells. Immune System Functions. Physical and Chemical Barriers Innate Immunity. Nonspecific Resistance Innate Immunity. The second line of defense is nonspecific resistance that destroys invaders in a generalized way without targeting specific individuals:. Specific Resistance Acquired Immunity.
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