Chapter 10.3: Immune System

what are pathogens

harmful microorganisms that cause disease

what are leukocytes

white blood cells

what are lymphocytes

T cells, B cells, natural killer (NK) cells

where do leukocytes originate from and found

bone marrow, lymphatic organs

where do T cells mature

thymus

where do B cells mature

bone marrow

what is the first line of defense and generates a nonspecific immune response

innate immune system

what are the two parts of the innate immune system

external immunity, internal immunity

what is external immunity

physical/physiological barriers preventing pathogen entry

what are the physical/physiological barriers in external immunity

skin, hair, cilia, mucous membranes, chemical secretions, symbiotic bacteria

what is internal immunity

internal defenses activated by innate immune system to neutralize pathogens that have entered

what is the internal immunity composed of

inflammatory response, complement proteins, phagocytic, natural killer cells

what are a type of leukocyte responsible for the first part of inflammatory response

mast cells

what is the first part of inflammatory response known as

rally signaling

rally signaling step 1

mast cells sit in tissue in prep for injury

rally signaling step 2

if theres an injury, mast cells will release histamine dilating blood vessels

what is the result of mast cells releasing histamine to dilate blood vessels

increases blood flow, makes vessels more permeable to let immune cells into tissues

rally signaling step 3

mast cells release heparin

what is heparin

anticoagulant prevents blood clotting

what is the mnemonic for inflammatory response

SLIPR

what are inflammatory responses

swelling, loss of function, increased heat, pain, redness

what is the inflammatory response of swelling

permeable capillaries result in fluids leaking into tissues

what is the inflammatory response of increased heat

increased blood flow results in higher temp

what is the inflammatory response of pain

continuous pressure on nerve endings

what is the inflammatory response of redness

increased blood flow

how can a fever occur due to the inflammatory response

controlled by brain causing systemic response to kill pathogens with higher temps

what is the process of cells moving from capillaries to the tissues in order to fight pathogens

diapedesis

what are cells in the innate immune system with specific granules in their cytoplasm

granulocytes

what the types of granulocytes

neutrophils, eosinophils, basophils, mast cells

what are the types of leukocytes from highest to lower in quantity

neutrophils, lymphocytes, monocytes & macrophages, eosinophils, basophils

what is the mnemonic for the types of leukocytes from highest to lower in quantity

Never Let Monkeys Eat Bananas

what are neutrophils

phagocytes in innate immunity that make up over half of all leukocytes

what type of leukocyte is the most common type found in blood and are one of the first cells to be recruited to an inflammation site

neutrophils

what are B and T cells apart of

adaptive immunity that must be activated

what do natural killer (NK) cells do

attack virally-infected cells and cancerous cells

what do NK cells use to lyse cells

perforin, granzyme

what does perforin do in NK cells

create holes

what does granzyme do in NK cells

stimulate apoptosis

what are the most common type of leukocyte found in lymph

B and T cells

what are monocytes & macrophages

phagocytes in innate immunity

what are monocytes

immature form found in blood vessels

what are macrophages

mature form after diapedesis

what can macrophages also act as

antigen-presenting cells to activate adaptive immunity

what do eosinophils have

granules that can be released to kill pathogens

what do basophils contain

granules with histamine and heparin

what do basophils do

circulate as mature cells

what do dendritic cells do

scan tissues using pinocytosis and phagocytosis

what do dendritic cells act as

antigen-presenting cells, migrate to lymph nodes to activate adaptive immunity

what do macrophages and dendritic cells use to recognize conserved parts of microbes

toll-like receptors (TLRs)

what happens when macrophages and dendritic cells bind to toll-like receptors

triggers phagocytosis, activates innate immune system

how are interferons secreted by

virally-/bacterially- infected cells

what do interferons secreted by virally-/bacterially- infected cells do

bind to non-infected cells to prepare them for attack

what are anucleate cell fragments that are involved in blood clotting and in activating the innate immune system helping regulate macrophages and dendritic cells

platelets

what is a group of ~30 proteins that aid immune cells in fighting pathogens

complement system

what do the proteins in the complement system do

turn each other on through complement cascade activation producing large effect

complement protein actions

tags antigens for phagocytosis in opsonization, amplifies inflammatory response, forms membrane attack complex (MAC) poking holes in pathogens lysing them

what system is a specific immune response

adaptive immune response

what is an immunogenic foreign molecule and is the target of the immune response

antigen

what is the important part of the antigen that is recognized by the immune cell

epitope

what does the immune system use to recognize foreign cells and antigens

major histocompatibility complex (MHC)

what is MHC class I

surface molecule on all nucleated cells that present intracellular antigens

what is MHC class II

durface molecule on antigen-presenting cells that present extracellular antigens

when do autoimmune diseases occur

immune system attacks self MHC I

what do B cells control and how

antibody-mediated immunity (humoral immunity) by managing production and antibodies release

what is located on B cells and bind to antigen epitopes either free-floating or on APC

B cells receptors (BCRs)

what describes the development of one type of BCR for every B cell

clonal selection model

how do B cells divide

through clongal expansion

what do B cells divide into through clonal expansion

plasma cells or memory B cells

how are memory B cells the key to vaccinations

vaccines cause memory B cell production for later reactivation then cause massive antibody production

what are structurally identical to BCRs but freely circulate in blood and lymph

antibodies;immunoglobulins

what do antibodies contain

light and heavy chains linked together by disulfide bonds

what is the variable region

recognizers different antigens

what is the constant region

same for antibodies within the same class

what are the classes of antibodies

IgM, IgA, IgE, IgD, IgG

which class of antibody is present in a pentameric form and is the largest antibody

IgM

which class of antibody is present in a dimeric form and found most abundantly in bodily secretions

IgA

what is the first antibody to be produced

IgM

what antibody activates the complement system

IgM

through which antibody lets newborns receive passive immunity through breast milk by containing this antibody

IgA

which antibody is a monomer that is present on basophils and mast cells as antigen receptors

IgE

what happens when IgE is bound to an allergen

triggers histamine release and allergic reaction

which antibody triggers an allergic reaction

IgE

which antibody is a monomer with very little info known with only small amounds are produced

IgD

which antibody is a monomer that is the most abundant antibody in circulation

IgG

which antibody is the only one that can cross the placenta to give fetus passive immunity

IgG

which antibody helps the complement system

IgG

which antibody causes opsonization when it helps the complement system

IgG

what is opsonization

tags antigens and subsequent phagocytosis

which antibody helps igM activate the complement system

IgG

what do T cells control

cell-mediated immunity

how do T cells control cell-mediated immunity

directly acting on cells instead of sending antibodies out

what do T cell receptors (TCRs) do

bind only to one type of antigen per T cell

what do T cells undergo

clonal selection

what must T cells bind to be activated

antigens presented on APCs (antigen-presenting cells)

what are the ways antigens may be presented to T cells

MHC I and II presentation

what is MHC I presentation

T cells differentiate into cytotoxic T cells (CD8+) directly killing infected cells through perforin and granzymes

how are T cells different from NK cells

more specific and require antigen presentation

what is MHC II presentation

T cells differentiate into helper T cells (CD4+) releasing interleukins to boost innate and adaptive immunity

how does interleukins boost innate and adaptive immunity in MHC II presentation

attract innate immune cells, increase proliferation of other T and B cells

what refers to the immunity one organism gains from receiving the antibodies from another organism that already has that immunity

passive immunity