Week 3: Immunity Flashcards
1st Lymphoid Organs
Thymus and bone marrow
2nd Lymphoid Organs
Adenoids, tonsils, cervical nodes, thoracic duct, right subclavian vein, axillary nodes, spleen, peyer’s patches, inguinal nodes
Innate vs Adaptive Immunity
Innate: always there and ready to happen and happens quickly, but not efficient because its not specific
Adaptive: efficient because its very specific, but takes longer than innate to start
What cells are included in innate immunity?
Phagocytes, dendritic, complement, NK cells
Cells included in adaptive immunity?
B lymphocytes, antibodies, T lymphocytes, effector t cells
Types of adaptive immunity includes?
Humoral and cell-mediated immunity
What cells are involved in cell-mediated immunity? What is the function of cell mediated immunity? Does this immunity involve intracellular or extracellular microbes
T Cells
Helper T cells: Activate macrophages to kill phagocytosed microbes
Cytotoxic T cells: Kill infected cells and eliminate reservoirs of infection
Cells involved do not allow a hiding space for hiding. T lymphocites put microbes back out to be killed by phagocytes
- Intracellular Microbes
What is humoral immunity?
Blocks infections and elinniates extracellular microbes
What do B lymphocytes do?
Block infections and eliminate extracellular microbes,
Create antibodies
What do Helper T Lymphocytes do?
Activate macrophages to kill phagocytosed microbes
What do Cytotoxic T lymphocytes do?
Kill infected cells and eliminate reservoirs of infectio
What are antibodies? What are the different types of Antibodies?
An antibody/ immunoglobulin is a protein that is secreted by plasma cells in response to a specific foreign antigen
Types: IgG, IgM, IgA, IgD, IgE
What is IgG? Where are they found? What is their half life?
Predominant immunoglobulin (75-80%).
Found in intravascular (WBC, RBC) and interstitial fluids (Amino acids, sugars, fats) ; serum half-life is around 20 days
What is IgM? They make up how many % of immunoglobulins? What is their role? What is their half life?
Theyre huge and look like snowflakes.
- Around 10% of immunoglobulin;
-1st antibody to be produced in a primary immune response. - Hold into place so macrophages can eat them.
- Half life is under a week
What are IgA’s? They are the main class of antibodies where? How long do they persist for?
Main class of antibodies in external secretions. (Salivam tears, breast milk)
Protects body’s mucosal surfaces from infection. Persists for only 5-8 days.
What are IgD’s? What is their half life? Their function is to help what?
main antibody on the surface of B cells; half-life ~ 3 days; function thought to be to help activate B cells, thus, b cells are ready to provide immune response
What are IgE’s? They bind to what? What is their half life? Their function initiates what?
LEAST abundant immunoglobulin
binds to mast cells and basophils after antigen exposure
half-life ~6 h in plasma
when bound to basophils/mast cells, the half-life is much longer (weeks to months)
Function: initiates inflammation & allergic reactions (type 1 hypersensitivity); immunity against parasitic worms
What are hypersensitivity reactions? How many types are there? and what are they?
These are exaggerated or inappropriate immunologic responses occurring in response to an antigen or allergen.
Types:
I: Atopic, Anaphylactic
II: Cytotoxic
III: Immune Complex
IV: Delayed hypersensitivity
Hypersensitivity Reactions Type I. What antibodys is involved? What cells secrete them? They bind to what after?
Type 1: Atopic, Anapylactic
- B cells recognize antigen and secrete IgE. Then IgE bind to mast cells and basophils, then once reexposed to same antigen allergic reaction is triggered and inflammatory process begings
What are antigenic triggers of Type 1 Hypersensitivity Reactions?
Like allergies; bee sting, seafood, peanut proteins, drug allergies, etc.
What antibody is involved in Hypersensitivity reaction I?
IgE
Hypersensitivity Reaction Type II
Cytotoxic
What antibodies are included in hypersenstivity reaction II?
IgM, IgG.
- Bind to fixed antigen on surface of enemy cell, leading to cellular destruction (cell lysis)
Examples of type II reactions?
ABO transfusion reaction, hemolytic disease of newborn (erythroblastosis fetalis), myasthenia gravis, thyroiditis, hyperacute graft rejection, & autoimmune hemolytic anemia
