FINAL - Mod 13: Immunity, Mod 15: Msk Flashcards
what is specific defense of the immune system
responds to particular substances, cells, toxins, or proteins, which are perceived as foreign to the body and therefore unwanted or potentially dangerous.
The immune cells, or lymphocytes, and macrophages provide the specific mechanism for the identification and removal of foreign material.
what is nonspecific defense of the immune system
Inflammation.
Non-specific immune cells function in the first line of defense against infection or injury. Doesn’t differentiate between 1 pathogen and another
what are the components of the immune system?
lymphoid structures, immune cells, tissues, chemical mediators
What is the function of the lymphatic tissue and organs of the immune system? What does it contain?
contain many lymphocytes. Filter body fluids, remove foreign matter, immune response.
(responsible for immune cell production and development)
What is the function of the thymus in the immune system?
maturation of T lymphocytes
What is the function of Bone marrow in the immune system?
Produce all immune cells.
Source of stem cells, leukocytes, and maturation of B cells
What are Antigens (immunogens) ? they can activate the immune system to produce..?
Antigens are substances with unique protein markers on the outside that the immune systems recognizes and attaches to.
– are either foreign substances or human cell surface antigens that are unique in each individual (except identical twins).
– can activate the immune system to produce specific antibodies
Human MHC, also known as human leukocyte antigen (HLA) are self antigens. They are used to
detect changes in cell membranes; used to provide the close match for a transplant. individual labelling with HLA (except identical twins)
The immune system generally tolerates self-antigens on its cells, thus no immune response is initiated against the own cells. When the immune system no longer recognizes self-antigen, what happens and results?
Begins to attack its own cells/structures or organs, resulting in Autoimmune disease.
what initiates the immune response? Where does it develop from?
Macrophages.
Develops from monocytes; part of the mononuclear phagocytic system
Large phagocytic cells - intercept and engulf foreign material, then they do what which triggers what?
display the antigens on the cell membranes
- trigger lymphocytes (thus initiating immune response)
Macrophages also secrete what chemicals that play a role in the activation of additional lymphocytes and in the inflammatory response?
monokines, interleukins
What are B-cells? Where do they start out? Mature where? function?
= Produces antibodies with the assistance of T lymphocytes (plasma cells) or B memory cells – quickly produces antibodies during the subsequent invasion of the same antigen
- produced from the bone marrow stem cells; matured in the bone marrow.
- Act primarily against bacteria and viruses that are outside body cells.
What are T-cells? Where do they start out? Mature where? function? subtypes?
T lymphocytes = white blood cells.
produced from the bone marrow stem cells; matured in the thymus.
- Involved in cell-mediated immunity
- They attack the invader directly
Subtypes: cytotoxic T killer cell, helper T cells, memory T cells
What immunity are T-cells responsible for?
Involved in cell-mediated immunity
What immunity are B-cells responsible for?
humoral (antibody-mediated) immunity
What is the primary cell of the immune system called?
Lymphocytes
What are antibodies?
Antibodies are made by immune system to counter-act antigens.
How do T-cells work (attack the invader) in the immune system?
They attack the invader directly
How do B-cells work (attack the invader) in the immune system?
They create antibodies. The antibodies attack the invaders.
What are the 2 steps in acquiring immunity? Describe each
1) Primary Response — occurs after the first exposure to an antigen. The immune system recognizes the antigen as foreign and starts to create antibodies. These antibodies take 1-2 weeks to form
2) Secondary Response — occurs on subsequent to the antigen. The body recognizes the antigen and sends out antibodies right away to fight it. This response is intense and sudden. This response results in higher levels of antibodies than the primary response
What is the antigen-antibody relationship?
o Antibodies bind with the specific matching antigen, destroying it. This specificity of antigen for antibody, similar to a key opening a lock, is a significant factor in the development of immunity to various diseases
which immunoglobulin is the most abundant type of antibody and is found in body fluids? Protects against?
IgG - protects againsts bacterial and viral infections
which immunoglobulin antibody is found in secretions (tears, saliva, mucous membranes, colostrum)?
IgA
which immunoglobulin antibody is found mainly in the blood and lymph fluid and is the FIRST antibody to be made by the body to fight a new infection (first to increase immune response)?
IgM
which immunoglobulin antibody is associated mainly with the allergic response (causes release of histamine and other chemicals); results in inflammation
IgE
which immunoglobulin antibody is attached to B cells and activates B cells?
IgD
Immune system: What is the complement system? Frequently activated during? with? results?
a group of inactive proteins circulating in the blood; activated during an immune reactions (with IgG/M)
Results in cell damage and further inflammation
Chemical mediators are involved in
inflammation and immune reactions, dependent on the particular circumstances
Difference between active and passive immunity
- Active immunity: Develops when the person’s own body develops antibodies or T cells in response to a specific antigen; process takes a few weeks, but results lasts for years
- Passive immunity: Occurs when antibodies are transferred from one person to another; effective immediately, but only temporary (no memory)
What are 4 ways of acquiring immunity? Describe each
- Active natural immunity – direct exposure to an antigen
- Active artificial immunity - a specific antigen purposefully introduced into the body and stimulates the production of antibodies (i.e. immunization)
- Passive natural immunity – IgG transferred form mom to fetus across the placenta and breastmilk
- Passive artificial immunity – injection of antibodies from a person or animal into a second person
Describe the steps involved in a Type I hypersensitivity
reaction - First Exposure
1) The first exposure to the allergen
2) The immune system recognizes the allergen as harmful and creates antibodies (lgE) to that allergen.
3) These antibodies attach themselves to mast cells; the mast cells are now sensitized
Describe the steps involved in a Type I hypersensitivity reaction - Second Exposure
4) The body recognizes the allergen and the sensitized mast cells release histamine
5) Histamine triggers the inflammatory response in nearby blood vessels and tissues — symptoms manifest (edema, redness, puritis, drainage)
What are mast cells and what do they do?
Located in tissues, release chemicals such as histamine, heparin, and bradykinin in response to injury or foreign material.
What are the 4 hypersensitivity reactions?
Type I: Allergic reaction
Type II: Cytotoxic hypersensitivity
Type III: Immune complex hypersensitivity
Type IV: Cell-mediated or delayed hypersensitivity
Describe Type II: Cytotoxic hypersensitivity and give example
◦ Antigen present on the cell membrane (self or non-self)
◦ IgG react with this antigen, causes destruction of the cell
◦ Example: blood incompatibility (ABO type, Rh factor)
Describe Type III: Immune complex hypersensitivity and give example
◦ Antigen-antibody complex deposits in tissue (often blood vessel walls); activates complement => inflammation and tissue destruction
◦ Example: rheumatoid arthritis
Describe Type IV: Cell-mediated or delayed hypersensitivity and give example
◦ Delayed response by sensitized T cells to antigens, resulting in release of chemical mediators that cause inflammatory response and antigen destruction
◦ Example: TB test (Mantoux skin test), contact dermatitis
What happens with the release of histamine?
Causes vasodilation and increased vascular permeability or edema, contraction of bronchiolar smooth muscle, and pruritus
How do autoimmune diseases occur? what do they effect? What do autoantibodies refer to?
Examples?
◦ Occur when the immune system cannot distinguish between self and nonself antigens – develop antibodies to own cells/cellular material
◦ Can affect single organs/tissues or can be generalized
◦ Autoantibodies: antibodies formed against self-antigens
- Ex. Hashimotos thyroiditis (effects single organs); Systemic Lupus Erythematosus (SLE) (Chronic inflammatory disease – affects a number of systems)
Causes of immunodeficiency: Primary vs Secondary immunodeficiency
o Primary immunodeficiency: basic developmental failure somewhere in the system
– Due to genetic or congenital abnormalities
o Secondary immunodeficiency: loss of immune response due to specific causes
– Infection, splenectomy, liver disease, malnutrition, immunosuppressants, radiation, chemotherapy
• When a lymphocyte further specializes, what does it become
cells that have the special function of recognizing and reacting with antigens in the body. The two groups of lymphocytes, B Lymphocytes and T lymphocytes, determine which type of immunity will be initiated
What is essential to be done before undertaking an invasive procedure that carries an increased risk of organisms entering the body to anyone in an immunodeficient state?
that prophylactic antimicrobial drubs (preventive antibiotics) be administered to anyone in an immunodeficient state
What is a broken bone? Medical term for broken bone?
o Medical term = Fracture. Break in the rigid structure and continuity of a bone
What is a soft tissue injury to the tendon called?
Strain
What is tendon connective tissue for?
connects muscle to bone and is capable of withstanding tension
What is a soft tissue injury to the ligament called?
Sprain
What is a ligament connective tissue for?
- Direct attachment between two bones. Serves to support the internal organs and hold bones together in proper articulation at the joints.
What is a joint separation? Medical term for joint separation?
o Dislocation - The separation of two bones at a joint with loss of contact between the articulating surfaces
o causes soft tissue damage (ligaments, nerves, blood vessels) as the bone is pulled away from the joint
What are the 5 stages of bone healing?
- Hematoma
- Granulation tissue
- Procallus (fibrocartilage)
- Bony callus
- remodeling
Stage 1 of bone healing: Hematoma - describe
blood clot forms at the fracture site
Stage 2 of bone healing: Granulation tissue - describe
using hematoma as the base, granulation tissue (new vascular tissue) grows – phagocytic cells migrate to here to remove debris and fibroblasts migrate to here to lay down new collagen fibers
Stage 3 of bone healing: Procallus - describe
Procallus – fibrocartilage “collar”forms at the site – this is not strong enough to bear weight but is the preliminary repairing in the bone.
o Osteoblasts begin to generate new bone to fill in the gap
Stage 4 of bone healing: Bony callus - describe
Procallus is replaced by bony callus ** bone repair via new bone formation, not by scar tissue
Stage 5 of bone healing: Remodeling - describe
Repaired bone remodeled – excessive bone in the callus is removed and more compact bone is laid down and eventually the bone assumes a normal appearance