Immunology Flashcards
what is the function of the immune system? (2)
- to defend the body against invading infectious organisms and abnormal cells
- rids the body of damaged cells and debris
is an immune response always helpful?
nope, can be helpful or harmful
what is an antigen?
foreign molecule capable or inducing acquired immune responses
what are leukocytes?
white blood cells, immune cells
what is a lymphocyte?
an antigen-specific leukocyte
what are antigen-presenting cells? (APCs)
cells capable of presenting antigens to CD4+ T cells
what are the 3 lines of defense of the immune system?
- physical barriers
- nonspecific internal defenses
- specific immune response (adaptive)
what are the 2 physical barriers of the immune system?
- the skin
- mucous membranes
give 5 nonspecific internal defenses of the immune system
- phagocytosis
- natural killer (NK) cells
- inflammation
- fever
- other
what are the 2 arms of the specific/adaptive immune response?
- cell-mediated (T cell)
- humoral (B cell)
what is the goal of vaccines?
to activate adaptive immunity
what is the lymphatic system?
a secondary circulatory system that drains extracellular fluid from tissues
how dooes the cardiovascular system relate to the lymphatic system and immunity?
cardiovascular pressure drives fluid into lymphatic system into lymph nodes where APCs hangout and sample all your shit before the lymph fluid is filtered back into the bloodstream; helps keep immune system robust
what are macrophages?
large irregularly shaped cells
what do macrophages do and how?
- kill microbes by ingesting them through phagocytosis
- the vaculose containing the bacterium fuses with a lysosome
- fusion activates enzymes that kill the microbe
when you get a cut, what happens? include cytokines, WBCs, APCs, antigens, lymph nodes, T and B cells
cytokines make vessels leaky so WBCs can follow cytokines to the damage; then APCs go to lymph nodes and present antigen to T and B cells to activate adaptive immune response
describe cell-mediated adaptive immunity
involves production and activation of T lymphocytes (a type of WBC)
give 3 general classes of T cells
- CD4+
- CD8+
- suppressor T cells
describe humoral adaptive immunity
involves production of antibodes (Ab) to antigens
give 3 basic WBCs involved in humoral adaptive immunity
- B cells
- plasma cells
- memory cells
describe how humoral immunity is antibody dependent
an antibody is produced in response to an antigen
what do vaccines represent with humoral immunity?
they are a “challenge” to retrain immunity
what do plasma cells morph from? what do they do?
plasma cells morph from B cells and secrete antibody
list and describe 5 functions of antibodies
- neutralization: renders particle no longer pathogenic
- agglutination: antibodies bind antigen and clump up
- activate complement system: formation of membrane attack complex
- stimulate phagocytosis: via opsonization
- stimulate NK cells
what do CD4+ T cells do? (2)
- stimulate antibody production by B cells
- stimulate activity of other T cell and macrophages
(the conductors of immune repsonse)
what 4 kinds of cells do CD8+ T cells destroy?
- self cells which contain antigens
- cancerous cells
- cells that harbor viruses
- transplanted cells
what do suppressor T cells do?
inhibit the activity of both T and B cells
what are CD8+ T cells?
effector T cells whose purpose is to attack self cells that harbor intracellular infections
what do CD8+ T cells do?
recognize self-cells through MHC Class I molecules presenting foreign peptides
what do innate mechanisms of the immune system do?
function non-specifically to block establishment of an infection
what do adaptive mechanisms of immunity do?
specifically target antigens associated with a specific pathogen
describe the immune mechanisms thata re invoked in a particular infection?
tailored to the site of infection and the type of pathogen being targeted
what controls all immune responses?
cytokines
