Immune System Flashcards
Antigen Recognition
Binding of a T cell or B cell to an antigen presented by a macrophage & the identification of that antigen as nonself material
Special function of Immune System
1) Identify threat
2) Mount an attack
3) Eliminate pathogen
4) Remember process…… IN 10 DAYS
- If it takes months or years (prolonged reactions) leads to Chronic Inflammation
MHC II (name, aka, & description)
- Major Histocompatibility Complex II
- AKA HLA (Human Luekocyte-Associated) Antigens
- Self antigens found on WBC surfaces
MHC II (function, 2)
1) Acts as a “security badge” that identifies the WBC as self material
2) Important to Macrophages that present nonself antigens on their surfaces (because it prevents them from being mistaken as nonself)
Cytokine (3)
1) a small molecule used to communicate between specific cells in the body
2) classified as a hormone
3) Types= Interleukins, Interferons, & Lymphokines
Interleukins (2)
1) Cytokins used by WBCs for communication with each other
2) IL-1, IL-2, IL4, & IL-5
IL-1 (Interleukin-1) (3)
1) Chemical signal released by a macrophage when it binds to a T cell & a B cell
2) Helps to stimulate division & differentiation of both the T cell & the B cell
3) Helps to trigger the release of IL-2 from a T cell
IL- 2 (Interleukin-2) (2)
1) Chemical signal released by an activated helper T cell (meaning it has been stimulated by the binding of a macrophge by IL-1).
2) Helps to stimulate the division & differentiation of both T cells & B cells
IL-4 & IL-5 (2)
1) Chemical signals released by the activated helper T cell
2) Both chemicals stimulated division & differentiation of B cells & antibody production by plasma cells
Autoimmunity (2)
1) An immune response against one’s own tissues
2) Associated with a failure of the immune system to discriminate between self and nonself
Allergy (2)
1) aka hypersensitivity
2) An overreaction to an antigen that causes injury to body tissues
Passive Immunity (3)
1) Immunity without exposure to antigens
2) Involves the transfer of antibodies into a recipient with no anamenstic response in that recipient
3) Can be natural or artificial
Active Immunity (3)
1) Immunity resulting from exposure to antigens, that triggers the activities of B cells, T cells, & antibodies in the body
2) Results in an anamnestic response
3) Can be natural or artificial
Immunization (2)
1) the artificial stumulation of active immunity through the medical introduction of a harmless antigen into the body
2) Produces anamnestic response that protects the patient against potentially dangerous bacteria, viruses, or toxins that contain that antigen
What are the divisions of the human Immune System?
1) Nonspecific Immunity (aka Natural or Innate Immunity)
2) Specific Immunity (aka Acquired or Adaptive Immunity)
What does non-specific mean?
Cells in the immune system that can distinguish an invader from a human cell but can’t distinguish one invader from another
What are 2 types of Innate defenses?
Surface barriers & Internal defenses
What are the Internal defenses of the Innate (non-specific) defense system? (5)
1) Antimicrobial proteins
2) Fever (fast acting, working within minutes to hours)
3) Inflammation
4) Natural Killer cells
5) Phagocytes
What is the trade off for the speed of innate responses?
Response has no memory- meaning it will respond to the same pathogen in the exact same way, no matter how many time it sees the pathogen.
What are the Surface Barriers of the Innate (non-specific) defense system? (2)
Skin & Mucous Membranes
What are the 2 types of Adaptive (specific) defense system?
1) Humoral immunity (B cells)
2) Cellular immunity (T cells)
Characteristics of Nonspecific Immunity (aka natural or innate immunity) (4)
1) Present at birth
2) Lasts throughout life
3) Generalized & untargeted
4) Consists of barriers, some chemical defenses, phagocytosis, & the inflammoratory response
Characteristics of Specific Immunity (aka acquired or adaptive immunity) (4)
1) Develops when we are exposed to nonself (foreign) material
2) Produces Anamnestic Response
3) Identifies and targets specific nonself materials for removal or destruction (SPECIFIC TO EACH INVADER)
4) Involves T cells, B cells, Antibodies, & their activities
What is the trade off for the adaptive immune response being specific & diverse?
Relies on cells being primed or activated so they can fully differentiate into the right kind of fighter to kill a pathogen –> CAN TAKE WEEKS.
Anamnestic Response
1) Allows a form of immunological memory to be created
What are the nonspecific resistance mechanical barriers? (4)
1) Skin
2) Mucous membranes
3) Mechanical flushing (urination, defecation, vomiting, salvation, & tear production)
4) Nasal hairs
What are the chemical barriers of nonspecific resistance? (3)
1) Acids (in skin, stomach, & vagina)
2) Digestive enzymes
3) Lysozyme- an antibacterial enzyme found in tears, blood, & tissue fluids)
Interferons (IFNs) (3)
1) proteins produced by body cells
2) Chemical mediator of innate immunity
2) protect nearby cells against viral infections (alpha & beta IFNs)
3) regulate the activity of immune system cells in tumors (gamma IFN)
Complement (3)
1) group of 20 proteins that protect the body by destroying abnormal cells or enhancing other components of immunity
2) make up 10% of the Globulin part of plasma proteins
3) circulate the blood in an inactive form until activated in the Complement Cascade
The Complement Cascade
1) A series of reactions in which each component of the series activates the next component
2) Begins with activation of Complement protein
3) Classic Pathway & Alternative Pathway
4) 7 total steps
Classic Pathway of the Complement Cascade (3)
1) Adaptive/Specific/Acquired Immunity (Steps 1-7)
2) Begins when antigen-antibody complex binds to C1 & activates C4
3) Activated C4 connects with C2 and activates C3.
Alternative Pathway of the Complement Cascade (4)
1) Innate/Natural/Nonspecific Immunity (Steps 3-7)
2) Initated when C3 protein spontaneously activates
3) IF C3 does not interact with a microorganism it is quickly inactivated.
4) IF it’s actived by combining it with a foreign cell (virus or bacteria) then cascade starts
What are the steps of the Complement Cascade? (4)
- Once C3 is stabilized buy either the classical or alternative pathway it stimulates cascade
1) C3 activates C5 –> C9
2) C3, C4, C5, & C7 promote inflammation, chemotaxis, & phagocytosis
3) C5-C9 combine to form a MAC (membrane attack complex)
What are Chemotactic Factors? (3)
1) Chemical signals that attract WBCs
2) Concentration controls WBC movement (Chemotaxis)
3) Include Complement, Leukotrienes, Kinins, & Histamines
What effects are produced by the chemicals released from basophils, mast cells, & eosinophils? (2)
Produce an inflammatory response & allergic reactions
How do NK cells function? (3)
1) Generalized function of recognizing classes of cells (tumor cells, etc.) as opposed to specific tumor cells
2) No memory response so part of innate immunity
3) Variety of methods to kill their target cells (including releasing chemicals that damage plasma membranes and cause cells to lyse.
What types of tissue damage cause an inflammatory response? (4)
1) Trauma
2) Burns
3) Chemicals
4) Infections
Stages of Inflammation (7)
1) Initiated by release of inflammatory chemicals (Histamine, Prostagladins, Cytokines)
2) Vasodilation = Hyperemia (increased blood flood)
3) Phagocyte mobilization
4) Through diapedesis, neutrophils squeeze through blood vessel walls and rely on chemotaxis to reach site of injury
5) Neutrophils perform phagocytosis
6) Monocytes leave blood vessels in same manner to become Macrophages that go to site of injury (2nd)
7) Macrophages continue phagocytosis
What are the symptoms of local inflammation? (4)
1) Redness
2) Heat
3) Pain
4) Swelling
What are the symptoms of systemic inflammation? (3)
1) All same as local inflammation
2) Fever
3) Shock and death due to widespread blood/fluid loss
Fever (5)
1) Stimulated during systemic inflammation
2) Caused by release of Pyrogens by neutrophils & macrophages
3) Affect hypothalamus’ ability to regulate blood temperature
4) Causes heat production & heat conservation to increase which raises body temp
5) Rise in body temp promotes phagocytosis and inhibits growth of microorganisms
