Biology: Chapter 10: The Immune System

Science 00000 with N/a at University of Texas - Austin

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By: Kathy Mostajeran
Created: 2011-06-01
Size: 55 flashcards
Views: 7

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Leukocytes

vital for specific immunity
born in the bone marrow
may contribute to either innate immunity or adaptive immunity
two types: granulocytes and agranulocytes

Granulocytes

include neutrophils, eosinophils, and basophils

Agranulocytes

include the lymphocytes

Lymphocytes

responsible for

antibody production
immune system modulation
targeted killing of infected cells

Monocytes

primarily mcarophages
agranulocytes
serve as nonspecific sanitation workers that travel the body picking up debris, both foreign and domestic

B-cells

lymphocytes that contribute to adaptive immunity
mature in the spleen
activated B-cells secrete antibody molecules that bind to antigens and destroy the invader directly or mark it for attack by other cells
spawn memory cells that promptly eliminate invaders encountered before

T-cells

lymphocytes that contribute to adaptive immunity
mature in the thymus
T-cells recognize antigens displayed on cells
Some T-cells help to activate B-cells and other T-cells
other T-cells directly attack infected cells
spawn memory cells that promptly eliminate invaders encountered before

Non-specific Immune response

innate immunity
the responses cells can carry out without learning
organisms cannot make the innate defense mechanisms more effective over time

Specific Immune Response

adaptive immunity
developed as immune cells learn to recognize and respond to particular antigens

Humoral Immunity

specific immune system
driven by B-cells and antibodies

Cell-mediated Immunity

specific immune system
provided by T-cells

Innate Immune System

acts near entry points into the body and is ready
includes antimicrobial molecules and phagocytes
dendritic cells and macrophages activate an inflammatory response by secreting proteins called cytokines that trigger an influx of defensive cells from the blood
these defensive cells are more phagocytes- mostly monocytes (which mature into macrophages) and neutrophils

Adaptive Immune System

if the innate immune system fails to contain a pathogen, adaptive immunity kicks in = a later but highly targeted attack against the specific invader
based on T-cells and B-cells
forms immunological memory = improves the effectiveness and alacrity of the immune response

Antigens

proteins and carbs present on the outer membrane of most cells
allow immune systems to distinguish between self and nonself
allow immune system to recognize our self-antigens and antigen-presenting cells as non-threatening
foreign antigens will trigger an immune response

Autoimmunity

when the immune system fails to learn the distinction between self and non-self it may attack self-antigens as if they were non-self
hypersensitivity reaction

Allergies

when immune system misidentifies a foreign antigen as dangerous when it isn't

hypersensitivity reaction

skin

first line of defense
provides a physical barrier between the outside world and internal organs to keep microbes out
sweat contains an enzyme that attacks bacterial cell walls

lysozyme

mucous membranes (secreted in tears and in saliva) produce this nonspecific bactericidal enzyme

macrophages

if foreign particles make it past the skin they will be phagocytized by macrophages
may be called to a site of inflammation by chemicals such as histamine
works well against extracellular pathogens (like bacteria)

histamine

causes vasodilation
allows macrophages to move out of the blood stream and into the tissue

Interferon

produced by immune cells and cells that have been infected with viral particles
a protein that prevents viral replication and dispersion
directed against a virus but not against specific viruses = nonspecific defense

Macrophage

innate immunity
engulfs and consumes pathogen invaders

Mast cell

innate immunity
releases histamine and other chemicals that promote inflammation

Granulocyte

innate immunity
three cell types with tiny granules in their interior = neutrophil, eosinophil, and basophil
participate in the inflammatory response

Dendritic cell

innate immunity
present antigens to adaptive immune cells to induce the cells to attack bearers of the displayed antigens

Natural Killer Cells

innate immunity
cell destroys the body's own cells that have become infected with pathogens
also goes after cancer cells

B-cells

adaptive immunity
antigens stimulate this cell to divide and produce antibodies that neutralize invaders or tag them for killing

T-cells

adaptive immunity
killer T-cells: destroys an infected cell in which it detects the presence of antigens
helper and regulatory T cells: coordinate the immune response

Humoral immunity

involves the production of antibodies
may take as long as a week to become fully effective

Antibodies

specific to the antigens of the invading microbe
produced by B-cells

B-cells

lymphocytes that originated in the bone marrow
matured in the spleen and lymph nodes
only make 1 antibody but we have many B-cells so our immune system can recognize many antigens
don't constantly produce antibodies because production is energetically expensive

Immunoglobulins (Ig)

antibodies
bind to their specific antigens to either:

1. attract other leukocytes to phagocytize those antigens immediately
2. agglutinate with the antigens to form largcomplexes that can be phagocytized

Y-shaped molecules made up of 2 identical heavy chains and 2 identical light chains that are held together by disulfide linges and noncovalent interactions

Antigen binding region

at the two tips of the Y-shape of each antibody
there are specific polypeptide sequences that will bind only 1 specific antigen sequence

Constant region

remaining part of the antibody molecule that is not the antigen binding region
involved in recruitment and binding immune modulators (like macrophages)

Production of B-cells

don't constantly produce antibodies because production is energetically expensive
wait in the lymph nodes for their particular antigens to come along
upon exposure to the correct antigen: proliferation will occur and two types of daughter cells are produced: plasma cells and memory cells

Plasma cells

produce large amounts of antibodies
eventually die off

Memory cells

stay in the lymph nodes for use upon being re-exposed to the same antigen
can last a life-time
forms the basis of the efficacy of vaccinations

Primary response

initial activation of a B-cell
takes 7-10 days
plasma cells are utilized

Secondary response

when the same microbe is encountered again: memory cells produce the antibodies specific to
more rapid and robust

Cell-Mediated immunity

involves the T-lymphocytes

T-cells

originate from the same set of stem cells in the bone marrow as B-cells
mature in the thymus
form memory T-cells: causing a more robust response to the next exposure of the same antigen

Helper T-cells

also called T4 cells because they express the CD4 cell-surface protein
coordinate the immune response by secreting chemicals called lymphokines
note: destroyed by HIV

Lymphokines

capable of recruiting other immune cells (like plasma cells, cytotoxic T-cells, and macrophages) and increasing their activity

Cytotoxic T-cells

also called T8 cells because they express the CD8 surface protein
capable of directly killing virally infected cells by secreting toxic chemicals
recognize transplanted cells as non-self and try to destroy them
form memory T-cells

Supressor T-cells

another group of T8 cells
help tone down the immune response once infection has been adequately contained

Immunosuppressants

drugs that can prevent activation of the immune system
used for organ transplants
used for autoimmune disorders

Active Immunity

immune system is stimulated to produce antibodies against a specific pathogen
can be exposed through natural or artificial means

Natural exposure

antibodies are generated by B-cells once an individual becomes infected

Artifical exposure

vaccination
results in the production of antibodies but the individual never experiences true infection
an injection containing an antigen that will activate B-cell to produce antibodies to fight the specific infection is given
the antigen is weakened or killed form of the microbe or may be a part of the microbe's protein structure

Passive Immunity

results from the transfer of antibodies to an individual
immunity is transient: only the antibodies and not the B-cells that produce them are given to the immunized individual

Humoral Immune Response: DNA vaccine

vaccine plasmids enter targeted cell
plasmids produce antigenic protein
antigenic protein is released from an inoculated cell
cytokines help active B-cells
antigen binding to the B-cell triggers release of antibodies from plasma cells and memory B-cell production

Cellular Immune Response: DNA vaccines

plasmids yield antigenic protein
cytokines prime cytotoxic T-cells for action
antigenic peptides are displayed by MHC class I to a primed cytotoxic T-cell
antigen binding causes cytotoxic T-cells to multiply and attack inoculated cells
activated cytotoxic T-cells bind the dying inoculated cell and release cell-killing signals or secretion as well was produce memory cytotoxic T-cells

Lymphatic system

type of circulatory system
made up of one-way vessels that become larger as they move toward the center of the body (toward the hart)
a venous system
vessels carry lymphatic fluid and join to comprise a large thoracic duct in the chest = which delivers the fluid into the left subclavian vein

Lacteals

smallest lymphatic vessels
collect facts in the form of chylomicrons from the villi in the small intestine and deliver them into the bloodstream bypassing the liver

Lymph nodes

swellings
contain immune cells (primarily B-cells)
these ares provide a place for antigens from microbes to first interact with the adaptive immune system and allow its activation
like a security checkpoint for fluid that is being returned from the peripheral tissues to the central circulation

About this deck

By: Kathy Mostajeran
Created: 2011-06-01
Size: 55 flashcards
Views: 7

About StudyBlue

“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis