Lymphatic and Immune System Lab: Immunity Response Flashcards
What are the three lines of defense against tissue injury?
Surface barriers, innate immunity, adaptive immunity
what do surface barriers do?
prevent the entry of pathogens into the body
What do surface barriers consist of?
skin and mucous membranes
what is innate immunity?
born with response, do not require exposure to a foreign agent to be produced
What does adaptive immunity do?
respond to foreign cells and molecule with unique set of cells and molecules for each individual threat
What is adaptive immunity?
require exposure to foreign agent to be produced
What is another name for adaptive immunity?
acquired immunity
What are responses of innate immunity?
inflammation and fever, granulocytes and macrophages, and antimicrobial proteins
When are inflammatory mediators released?
when cells are damaged by microorganisms, foreign cells, toxins, viruses, or trauma they release the chemicals
What do inflammatory mediators attract?
first attract local immune cells to the area, which are primarily macrophages
What do inflammatory mediators stimulate?
local vasodilation, increased capillary permeability, increased sensitivity to pain
What does local vasodilation cause?
the area to become warm and red
What does increased capillary permeability cause?
cause the area to become swollen
What is chemotaxis?
macrophages continue to release inflammatory mediators that attract other phagocytes (neutrophils) to the damaged areas
What do pyrogens do?
act on the hypothalamus to raise the body temperature “set point” and cause fever
What are the bodys main phagocytic cells?
granulocytes and macrophages
What do granulocytes and macrophages do?
They will nonspecifically ingest and destroy any foreign or damaged cells
How many times can macrophages ingest and destroy foreign/damaged cells?
repeatedly
How many times can neutrophils ingest and destroy foreign/damaged cells?
once, then they die
What happens to neutrophils when damage is accessive?
many neutrophils will go to one area and die and accumulate which leaves pus
What do eosinophils and basophils do with immunity?
can function as phagocytes but main role is to secrete inflammatory mediators such as histamine
What do antimicrobial proteins do?
nonspecifically attack and lyse invading organisms when activated
What is the complement system?
collection for more than 20 proteins made by the liver
What do complement proteins do?
lysing foreign cells, enabling phagocytes to function better and enhancing the inflammatory response
What does adaptive immunity primarily involve?
B and T lymphocytes
What do B and T lymphocytes respond to?
unique antigens or chemical markers
Where are antigens primarily located?
many molecules such as toxins and allergens, and on surface of all cells
What is humoral immunity also called?
antibody-mediated immunity
What is humoral immunity brought about by?
B lymphocytes and proteins they produce, antibodies
How is the humoral response initiated?
when a macrophage or T lymphocyte presents a specific B lymphocyte with its unique antigen, which causes the B lymphocyte to activate and differenciate into two cells ,plasma and memory cells, which will remember the antigen and permit a more rapid antibody response upon subsequent exposures
What do plasma cells secrete?
antibodies
What do antibodies to to antigens?
antibodies bind and agglutinate antigens and facilitate their destruction by phagocytes and other components of the immune system
What do antibodies activate?
Innate defenses, particularly complete defenses, and neutralize toxins such as venoms
What is cell mediated immunity mediated by?
T lymphocytes
What two T lymphocytes are used in cell mediated immunity?
Helper T cells (CD4) and cytotoxic T cells (CD8)
How do the cell mediated response begin/go?
begin when a macrophage ingests and antigen and presents it to the helper T cells that has a receptor to bind that specific antigen, T cells then secrete cytokines which activate cells of innate immunity such as macrophages, encourage inflammation, activate B lymphocytes and activate cytotoxic T cells, the activated cytotoxic T cells bind to cells whose antigens correspond to receptors to lyse and destroy them
What cells do Cytotoxic T cells target?
cells infected with viruses, intracellular bacteria, cancer cells, and transplanted cells
What can helper and Cytotoxic T cells turn into?
memory cells
What do bacterial infections lead to elevations in?
neutrophils that phagocytize the bacterial cells
What do viral infections and cancer cells tend to trigger?
cell mediated response and lead to elevated levels of cytotoxic T cells that lyse affected cells
What is nonspecific resistance?
prevents pathogenic invasion without target specific kinds of apthogens
What are physical barriers in nonspecific resistance?
skin, mucous membranes
What are chemical barriers in nonspecific resistance?
lysozyme, gastric juice
What is the first line of defense?
physical and chemical barriers
What is the second line fo defense?
phagocytic cells, inflammation, fever, natural killer
What is the third line of defense?
immune system, specific resistence
What does the third line of defense rely on detecting?
foreign antigens
What is activated when foreign antigens are detected?
T cells and B cells
What lymphocytes are activated first?
T cells
After activation of T cells what happens?
they either directly destroy the microbes or use chemical secretions, stimulate B cells to divide to produce antibodies
What does cell mediated immunity involve the activation of?
T cells by a specific antigen
What are immature lymphocytes produced from?
stem cells in red bone marrow
Where are T cells produced?
thymus
Where are mature T cells located?
blood, lymph, and lymphoid organs such as the lymph nodes and spleen
What are the three major types of T cells?
Cytotoxic T cells, Helper T cells, Memory T cells
What do cytotoxic T cells secrete?
lymphotoxin and perforin
What do lymphotoxin and perforin do?
trigger destruction of the pathogens DNA, and the latter creates holes in the pathogens plasma membrane resulting in a lysed cell
What do helper T cells secrete?
interleukin-2
What does interleukin-2 stimulate?
cell division of B cells and T cells
What do memory T cells do?
remain dormant after initial exposure, then if antigen presents again memory cells are stimualted to concert themselves into cytotoxic T cells and fight
What is the process of phagocytosis?
- Microbe attaches to phagocyte
- Phagocytes plasma membrane engulfs the microbe, forms a vesicle
- Vesicle merges with a lysosome which contains digestive enzymes
- digestive enzyme begins to break down the microbe, phagocyte extracts nutrients it can use leaving the indigestible material and antigenic fragments within the vesicle
- Phagocytes make protein markers and they enter the vesicle
- Indigestible material is removed by exocytosis, antigenic fragments bind to the protein marker and are displayed on the plasma membrane surface, this serves to activate T cells
What does antibody mediated immunity involve?
activation of B cells by a specific antigen, triggers B cells to transform into plasma cells that secrete antibodies, antibodies are transported into the blood and lymph to the pathogenic site
Where are B cells produced from?
stem cells in red bone marrow
What are B cells divided into?
plasma cells and B memory cells
What do plasma cells secrete?
antibodies
What do memory B cells do?
ensure a quick response for the same antigen
What is neutralizing antigen?
antibody binds to antigen forming an antigen-antibody complex , this forms a shield around the antigen preventing its normal function, prevents infection
What is activating compliment?
triggers a cascade reaction, some proteins cluster together to form a pore or channel that inserts into the microbial plasma membrane resulting in a lysed cell
What is precipitating antigens?
numerous antibodies can bind to the same free antigens in solution to cross link them, cross linked mass then precipitates out of solution making ti easier for phagocytic cells to ingest it by phagocytosis
What is facilitating phagocytosis?
an antigen-antibody complex acts like a warning signal to signal phagocytic cells to attack, binds to surface of macrophages
