Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
38 Cards in this Set
- Front
- Back
|
Immune System
The Body’s Defences |
Maintaining homeostasis in the body requires ways to quickly & continuously defend against the activities of pathogens. These defences are present at birth & provide immediate protection against a wide variety of pathogens & foreign substances.
|
|
|
The immune system has three main functions to ensure the body is protected and maintains homeostasis.
|
Protecting the internal environment from invading foreign organisms
Removing damaged cells from circulation Surveillance of the body to identify and guard against abnormal development and growth of cells |
|
|
In protecting the body the immune system has three identified lines of defence:
|
1.First Line of Defence: Innate or Non-Specific Defences
2.Second Line of Defence: internal defence; Inflammation 3.Third Line of Defence: Immune response |
|
|
Immune System Link
First Line of Defence: Innate or Non-Specific Defences |
http://uhaweb.hartford.edu/BUGL/immune.htm#cellmed
|
|
|
Second Line of Defence
Inflammation |
This occurs when the first line of defence is broken or overwhelmed
The body’s response to injury is inflammation. |
|
|
The three stages of inflammation are;
|
Vasodilatation and increased permeability of blood vessels
Phagocyte migration Tissue repair |
|
|
Vasodilatation and Increased Permeability of Blood Vessels
|
Release of chemicals such as histamines & kinins cause vasodilatation & increased permeability of blood vessels
This allows more blood and defence mediators such as antibodies, phagocytes & clot forming chemicals to enter the injured area The increased blood flow helps remove toxic substances from the area This produces the typical heat, pain, redness & swelling |
|
|
Phagocyte Migration or Emigration:
|
Phagocytes (neutrophils & monocytes) appear on the scene within hours of the inflammatory process
They leave the blood vessels & move into the tissues Macrophages arrive on the scene hours later They engulf the damaged tissue, worn out neutrophils and invading microbes Within a few days a pocket of damaged tissue & dead phagocytes form This is called pus Pus formation continues until the infection subsides At times the pus pushes to the surface of the body or into an internal cavity for dispersal |
|
|
Immune System Defences
Third Line of Defence: Immune response |
This occurs when the second line of defence is overwhelmed and cannot ward off the attack
The immune system recognises foreign pathogens and acts to inactivate or destroy them When it operates effectively it protects the body from a wide variety of pathogens as well as from abnormal body cells that form in the body This is called the immune response |
|
|
Carrying out immune responses
|
The immune system protects the body by responding to an invasion against what the body considers foreign. Immune tissue initiates this highly specific response directed at specific microbes or abnormal cells. Lymphocytes, assisted by macrophages, recognise foreign cells, microbes, toxins, & cancer cells & respond by launching a cell mediated immune response or an antibody-mediated (Humoral) immune response.
|
|
|
Lymphocytes are programmed as they are developing to:
|
Be able to recognise a specific antigen and to be able to bind to it (immunocompetent)
Recognise the body’s own antigens so they do not bind to and attack the body’s own tissues (self tolerance) |
|
|
Lymphocytes either become
|
T cell or B cells and they both exert their defence mechanisms in different ways. Each T or B cell develops a unique receptor on its cell surface to recognise and bind to a specific antigen
|
|
|
The first contact with the invading antigen
|
usually takes place in either the spleen or a lymph node. Depending on the type of antigen within the body either the B or T cell lymphocyte will activate an immune response. T cells provoke a cell mediated response and the B cells provoke an antibody mediated response
|
|
|
Watch this video on the cell medicated and the humoral medicated immune responses:
|
http://www.youtube.com/watch?v=lIVsvGDsMPM
|
|
|
Immune System Defences
Mediated Responses Antibody Mediated Immune Response |
B cells produce five different classes of antibodies (immunoglobulin): IgA, IgG, IgM, IgD & IgE
|
|
|
B cells produce five different classes of antibodies (immunoglobulin):
|
All of these hare located in different areas of the body and each have different roles
The immunoglobulin’s all have specific antigens that they target to assist in fighting off an invasion |
|
|
Click on this link to also review the different types of immediate and delayed allergic reactions
|
http://www.ecarf.org/index.php?id=56
|
|
|
What are the different types of allergies?
|
Two criteria are used in determining which group an allergy belongs to:
first, the reaction mechanism, and second, the reaction time – how long it takes for symptoms to appear. Type I - Immediate reaction (also known as anaphylactic reaction) Typ II - Cytotoxic Typ III - Immune complex allergies Typ IV - Delayed-onset allergies, cellular immune reaction |
|
|
Type I: Immediate reaction, anaphylactic reaction
|
This type of allergy is characterised by the immediate onset of symptoms (within seconds or minutes). Usually, the skin or mucous membranes are affected. Almost all Type I allergies are caused by proteins. Type I allegies are the most common allergies.
Beispiele sind: Hay fever (allergic rhinitis) Animal hair allergy Insect venom allergy Latex allergy Dust mite allergy Food allergy Medication allergy (local anaesthetics, antibiotics) Allergic asthma Urticaria Quincke's edema Anaphylactic shock |
|
|
Type II: Cytotoxic
|
You are here:
About Allergies » Science » What are the different types of allergies? What are the different types of allergies? Two criteria are used in determining which group an allergy belongs to: first, the reaction mechanism, and second, the reaction time – how long it takes for symptoms to appear. Type I - Immediate reaction (also known as anaphylactic reaction) Typ II - Cytotoxic Typ III - Immune complex allergies Typ IV - Delayed-onset allergies, cellular immune reaction Type I: Immediate reaction, anaphylactic reaction This type of allergy is characterised by the immediate onset of symptoms (within seconds or minutes). Usually, the skin or mucous membranes are affected. Almost all Type I allergies are caused by proteins. Type I allegies are the most common allergies. Beispiele sind: Hay fever (allergic rhinitis) Animal hair allergy Insect venom allergy Latex allergy Dust mite allergy Food allergy Medicat |
|
|
Type III: Immune complex allergies
|
Medication allergies are often type-III reactions. Foreign substances in the blood – such as medication – bond with antibodies, and then with the blood vessel walls in the smaller blood vessels, for instance, in the skin or kidneys. This leads to local inflammation, for instance, a skin rash, often in conjunction with haemorrhaging, skin damage, and itching.
Typical Type III allergies include: Vasculitis (inflammation of the blood vessels) Serum illness Alveolitis, Farmer’s Lung Nephritis (inflammation of the kidneys) Arthritis (inflammation of the joints) |
|
|
Type IV: Delayed-onset allergy, cellular immune reaction
|
Type IV allergies are characterised by the delayed allergic reaction. As with Type II allergies, allergens bind with cells, activating certain T-Lymphocytes, which recognize and attack these cells. This leads to damage in the surrounding tissues. This first contact sets off an immune reaction; whenever the T-lymphocytes encounter this allergen, it sets off a major allergic reaction. Because the (re-)activation of the T-lymphocytes takes some time, the allergic reaction first occurs 12 to 72 hours after contact with the allergen.
Typical Type IV allergies: Transplant rejection Contact allergies (e.g. nickel allergy) Tuberculin reaction (Tbc-Test) Rashes due to medication allergy |
|
|
Cell Mediated Immune Response
|
There are several types of T cells that have different roles in the cell mediated immune response
Active and Passive Immunity |
|
|
Active Immunity
|
This is naturally acquired due to the body encountering a viral or bacterial infection or artificially acquired through vaccination
Most vaccines contain dead or attenuated (living, but extremely weakened) pathogens which allows the immune system to develop antibodies without most of the signs and symptoms of the disease When the B cells encounter antigens they produce antibodies which results in active immunity. |
|
|
Passive immunity
|
Protection from antibodies are obtained not from your own body but from an outside source such as from the serum of the immune human or animal donor
The body’s own immune system does not respond when the antibodies enter the body as the B cells are not challenged by an antigen and do not develop memory cells The protection ends when the borrowed antibodies degrade Passive immunity can be naturally or artificially occurring |
|
|
Naturally:
|
Mother’s antibodies cross placenta & enter fetal circulation
IgG is the most abundant plasma antibody and is the only Ig antibody that crosses the placenta After birth there are small amounts of immunoglobulin’s in breast milk which assist in protecting the baby until they are able to develop their own antibodies |
|
|
Artificially:
|
Person receives immune serum or gamma globulin e.g. gamma globulin after exposure to hepatitis, antivenin or tetanus immunoglobulin for a tetanus prone wound
Rh (D) immunoglobulin: Rh -ve mothers receive within 72 hours post delivery of Rh +ve baby to prevent the formation of anti - D immunoglobulin’s which can cross the placenta during birth and start destroying the baby’s RBC’s. The effect lasts 2-3 weeks |
|
|
Autoimmune Diseases
Self’ and ‘Not-self’ |
The immune system has the ability to recognise what belongs to the body and what doesn’t.
The T and B cells assist the body to destroy and remove the antigens that do not belong to ‘the self’ This defence system sometimes goes haywire and the body is not able to recognise it’s self The immune system then produces antibodies called auto-antibodies These auto-antibodies sensitise T cells which then attack the tissues that belong to ‘the self’ Autoimmune disorders occur due to this process Common autoimmune disorders include SLE, Rheumatoid arthritis, Graves disease, and Multiple Sclerosis |
|
|
Review the list of autoimmune disorders on this link
|
http://www.heGlthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=/healthatoz/Atoz/ency/autoimmune_disorders.jsp
https://client.myoptumhealth.com/myoptumhealth/secure/home#home.search.searchLanding http://autoimmunediseaselist.com/a-to-z.php |
|
|
autoimmune disorder
|
There are more than 80 different types of autoimmune disorders.
|
|
|
What causes the immune system to no longer distinguish between healthy body tissues and antigens is unknown.
|
One theory holds that various microorganisms and drugs may trigger some of these changes, particularly in persons who are genetically prone to autoimmune disorders.
|
|
|
An autoimmune disorder may result in:
|
The destruction of one or more types of body tissue
Abnormal growth of an organ Changes in organ function |
|
|
An autoimmune disorder may affect one or more organ or tissue types. Organs and tissues commonly affected by autoimmune disorders include:
|
Red blood cells
Blood vessels Connective tissues Endocrine glands such as the thyroid or pancreas Muscles Joints Skin |
|
|
A person may have more than one autoimmune disorder at the same time.
|
Examples of autoimmune (or autoimmune-related) disorders include:
Hashimoto's thyroiditis Pernicious anemia Addison's disease Type I diabetes Rheumatoid arthritis Systemic lupus erythematosus Dermatomyositis Sjogren syndrome Lupus erythematosus Multiple sclerosis Myasthenia gravis Reactive arthritis Grave's disease Celiac disease - sprue |
|
|
Tests that may be done to diagnose an autoimmune disorder may include:
|
Erythrocyte sedimentation rate (ESR)
C-reactive protein (CRP) |
|
|
Treatment
|
The goals of treatment are to reduce symptoms and control the autoimmune process while maintaining the body's ability to fight disease. Treatments vary widely and depend on the specific disease and your symptoms.
Some patients may need supplements to replenish a hormone or vitamin that the body is lacking. Examples include thyroid supplements, vitamins, or insulin injections. If the autoimmune disorder affects the blood, the person may need blood transfusions. Measures to help with movement or other functions may be needed for autoimmune disorders that affect the bones, joints, or muscles. Medicines are often prescribed to control or reduce the immune system's response. Such medicines may include corticosteroids and immunosuppressant drugs such as cyclophosphamide or azathioprine. |
|
|
Expectations (prognosis)
|
The outcome depends on the specific disease. Most are chronic, but many can be controlled with treatment. Symptoms of autoimmune disorders can come and go. The sudden, severe development of symptoms is called a flare up.
|
|
|
Prevention
|
There is no known prevention for most autoimmune disorders.
|
