chapter 16: innate immunity- nonspecific defenses of the host Flashcards
what are the formed elements of the blood?
erythrocytes (RBCs), leukocytes (WBCs), thrombocytes (platelets)
function of erythrocytes (in blood)
transports gases (O2, CO2) and nutrients throughout the body
function of leukocytes (in blood)
major component of body’s defense against disease; “immunity cells”
function of thrombocytes (in blood)
form blood clots
order of white blood cells from most to least abundant
neutrophils - never lymphocytes - let monocytes - monkeys eosinophils - eat basophils - bananas
neutrophils
most common leukocyte; front line phagocytic cell; numerous, short-lived, disposable
eosinophils
fights multicellular parasites (helminths); specially attack worms & things too big to phagocytose; have some phagocytic activity
basophils
help create inflammatory response; often involved in allergies; also fights off ectoparasites (ticks)
monocytes
similar to macrophages; phagocytic antigen presenting cell (APC)
dendritic cells
have long branching extensions (tree-like); similar to macrophages; phagocytic antigen-presenting cell (APC)
lymphocytes (makes which two cells?)
B cells ➡ plasma cells➡ antibodies
T cells = cellular immunity & regulation; mature in thymus
helper T cells
release signals that B cells need to become antibody producing plasma cells; have glycoprotein (CD4) on their surface = CD4+
cytotoxic T cells
have glycoprotein CD8 on surface= CD8+
regulatory / suppressor T cells
CD4+; downregulate immune response; w/o these, fatal autoimmune reactions can cause death in approx. two years
natural killer cells
kill off any cells not displaying MHC class I; helps defend body against viruses & tumors; NK cells have similar job to cytotoxic T cells except NK cells don’t need to be activated to function….hence “natural killers”
innate defense
nonspecific defense mechanisms that come into play with an antigen’s appearance in the body
- ex) skin, complement, neutrophils
adaptive defense
specific defense mechanisms tailored to respond to a particular foreign invader; consists of antibodies & lymphocytes (humoral & cell mediated response)
- ex) B & T lymphocytes
importance of adaptive immune system
creates a memory (RAM= recognize, attack memory); activates classical pathway (antibody binds to antigen)
major histocompatibility complex (MHC)
proteins that self cells represent; determines self v. non-self
- ex) type I & type II
epitopes
displayed on MHC proteins; way to show what is going on in the cell/ what the cell has phagocytosed & what the cell is producing
what expresses type I MHC proteins?
nucleated cells & platelets
what expresses type II MHC proteins?
antigen-presenting cells (APCs)
