Immune System

As long-lived multicellular organisms, we need protection against

pathogenic organisms.

only a small percentage of microbes are

pathogenic

microbes that are pathogenic are very good at

invading our tissues when getting past certain barriers

our immune system defends against

viruses, bacteria, protozoans, fungi, and parasitic animals

what division of the iminnune system is non specific and has no memory

the innate immune system

components of the innate immune system can be found in what kingdoms of eukarya

animal and plant

what division of the immune system is high specific and has a memory

the adaptive immune system

what organisms is the adaptive immune system found in

vertebrate animals

the adaptive immune system which humans have gives us the ability to __

recover from an infection and then have protection when exposed to same pathogen later

____ and __ barriers create innate immunity

physical and chemical

what physical and chemical barriers contribute to our innate immunity

skin, normal flora found on skin, mucous and cilia in respiratory tract, low pH of stomach, antimicrobial peptides

pathogens are inactivated on the skin by __ and __

desiccation (drying out ) and the skin’s acidity

___ that coexist on the skin compete with pathogens preventing infection

beneficial microorganisms

eyes use __ to rinse away pathogens

tears

mucus membranes have __ that trap and rinse away pathogens

mucus secretions

__ in the nasal passages and respiratory tract push the mucus with the pathogens out of the body

cilia

the __ of the stomach inhibits growth of pathogens

low pH

blood __ bind and disrupt bacterial cell membranes

proteins

__ flushes pathogens from the urinary tract

urination

microbes have different __ than our cells

cell surface markers

anything that elicits an immune response (is foreign) is called an __

antigen

immune cells recognize pathogen associated patterns and __ the pathogen

phagocytize

many __ are involved with the innate immune system

white blood cells - leukocytes

inflammation is which division of the immune system in action

innate

what are the different things involved in inflammation

pain, heat, redness, swelling

what causes the redness and swelling in an inflammatory response

increased vascular permeability to allow WBCs to leave capillaries and enter tissues

why does an inflammatory response cause heat

body raises temp in attempt to slow growth of pathogenic bacteria

mast cells and NK cells are apart of what division of the immune system

innate

mast cells function

release histamine

natural killer (NK) cells function

kill virus infected of altered self cells (tumor cells)

adaptive immunity occurs after what

exposure to a pathogen or vaccination

without information from the __, the adaptive response could not be mobilized

innate immune system

what are the two types of responses in the adaptive immune system

cell-mediated immune response and humoral immune response

cell mediate immune response = _ cells

T cells

humoral immune response = _ cells

activated B cells and the antibodies they secrete

what type of cells are characteristic of adaptive immunity

lymphcytes

lymphocytes =

B cells and T cells

how long can it take for the adaptive immune system to be unregulated

days or even weeks

the innate immune system is ___

immediate

antigen =

macromolecule that is recognized by the immune system

a given antigen may contain several __ that are recognized by immune cells

motifs

each motif is a __

epitope

many _____ present antigens on their surface for B and T cells to recognized

cells of the innate immune system

cells that present antigens on their surface for B and T cells are called

antigen presenting cells

when presented with antigens, certain B and T cells become activated by

a highly specific antigen/epitope combination that they recognize

once activated what does the adaptive immune system do

divided to create an army of clones to neutralize the threat

B and T cells have __

memory

B cells are a __ response

humoral

where do B cell mature

in the bone marrow

what do B cells make

antibodies

what are antibodies

proteins encoded with DNA

each B cell produces antibodies with a specific variable region that

recognizes a specific epitope

antibodies can be __ or __

secreted or membrane bound on the B cell

each B cell secretes a single species of ___

antibody that recognizes a specific epitope

types of antibodies

IgA, IgD, IgE, IgG, IgM

antibodies can

neutralize a pathogen, tag a pathogen, trigger a cascade of chemicals (complement cascade)

what does antibodies neutralizing pathogens mean

prevent it from binding to a target

what does antibodies tagging a pathogen mean

tags a pathogen to be destroyed by a macrophage

what happens when an antibody triggers a complement cascade

a complement cascade is the release of a series of proteins that work together to destroy pathogens, form a complex that punches holes in membrane of pathogen

Major Histocompatibility Complex (MHC)

cell surface complexes that allow immune system cell to identify compatible or foreign proteins or cells

Major Histocompatibility Complex (MHC) function

present antigens from within the cell on the surface for the immune system cells to ‘see’

types of MHC

MHC class 1 and MHC class 2

where is MHC class 1 found

on all nucleated cells

if a cell in the body does not have MHC class 1 or has different MHC class 1 what happens

the cells are deemed foreign and destroyed

patients needing transplantation must have the same

MHC class 1

where is MHC class 2 found

only on antigen presenting cells

antigen presenting cells include

macrophages, B cells, dendritic cells

where do T cells mature

in the thymus

each T cell has a different

T cell receptor (TCR)

TCR function

recognize specific antigens presented in MHC molecules

what are the three populations of T cells

Th cells helper T cells (CD4 markers), Tc cells cytotoxic T cells (CD8 markers), Treg cells regulatory T cells

antigen presenting cells process antigens to be presented on the ___to a __ cell

MHC class 2 to a CD4 T helper cell

activated CD4 T cells release __ to up regulate B cells, cytotoxic CD8 cells, and others

cytokines

T helper cells will go through mitosis →

makes clones of itself (clonal expansion)

what are cytokines

proteins which control the growth and release of immune cells, cause inflammation recruiting cells to the site of infection

cell mediated response - B cells showing similar specificity for the antigen start

secreting antibodies

activated cytotoxic T cells do what

kill infected self cells or altered (tumor) self cells

if a cell is infected with a virus, it will present some of that virus on it’s MHC Class I, the Tc cell will then

force that self cell to go through apoptosis

Q: How does the variable region of an antibody secreted by one B cell differ from
another B cell?
Q: How does the variable region of the T cell receptor (TCR) of one T cell differ from
another T cell?

Gene rearrangement, during B and T cell development the region of the DNA that codes for the variable region “rearranges“ - this results in each B and T cell having unique variable region

b cells attack invaders ___ the cells

outside

T cells attack invaders ___ the cells

inside

leukocytes in blood migrate into

tissues along with fluid nutrients, ect.

leukocytes spend of their time in the __ system

lymphatic system

B T and other whit blood cells congregate in __ nodes

lymph

if there is something foreign that made it past the skin or mucosal membranes into the tissue, and it is detected in the lymph nodes what happens

clones of B and T cells specific for the antigen will be released into circulation to find more of that same antigen

primary response =

initial exposure to antigen/pathogen

in a primary response it takes __ for B and T cells to up-regulate and mount a full response

days to weeks

primary response- after recovery B and T cells specific to that antigen will

remain and circulate (up to decades)

secondary response =

second exposure to same antigen/pathogen

on a secondary response memory cells will respond much __

faster

the much faster response in a secondary response results in

an individual either not getting sick or being able to recover faster

vaccination initiates the __

primary immune response

when a person is exposed to a pathogen after having the primary response from a vaccination a secondary response will hopefully

prevent/lead to a faster clearance of the pathogen

vaccines cause an immune response but there is no

active disease

chronic inflammation (immune system issues)

can cause damage to tissues

allergies (immune system issues)

immune system overreaction to an antigen

autoimmunity (immune system issues)

recognizes self antigen as being foreign, resulting in tissue/organ damage

immune reaction where an antibody-mediated immune response occurs within minutes of exposure to a harmless antigen is what

hypersensitive/allergies

what is immunodeficiency

failure, insufficiency, or delay on the response of the immune system which may be acquired or inherited

what are the two types of immunodeficiency

primary and acquired