Week 3 Immunity Flashcards
Immunity refers to?
All the defenses that protects us against disease
How do infections occur? (4)
Portal of entry
Virulence
Dose
The individual
Virulence refers to?
How aggressive is the pathogen
-the organisms power to overcome the defenses of the host; toxin production
What are the 2 lines of defense in immunity
Innate
Adaptive
Innate defenses
Are inborn
Rapid, fairly non specific, can help prevent or slow infections
Adaptive defenses
Slower, specific to a pathogen, can completely eliminate the disease
What are the first line of defense which are innate barriers? (4)
The skin
Mucous membranes
Body secretions
Reflexes (sneezing/coughing/vomiting)
Second line of defenses include innate cells and chemicals such as (5)
-Phagocytosis (neutrophils & macrophages)
-Natural killer cells
-cytokines and other chemicals (interferon & complement)
-inflammation
-fever
In phagocytosis white blood cells take in and destroy
Waste and foreign material
(Neutrophils and macrophages)
Natural kill cells is a type of lymphocyte found in
Lymph nodes
Spleen
Bone marrow
Blood
Natural killer cells recognizes body cells with abnormal membranes and secretes?
Proteins that breaks down the cell membrane
What are interferons
*hint think interfere
Proteins released from virus infected cells that prevent nearby cells from producing more virus
What are cytokines
Essential part of the inflammatory process. A peptide (small protein) produced by immune cells or other body cells that are used for cellular signalling
Complement refers to
Specialized proteins in blood that are activated by immune responses
Complement promotes what 2 things
Inflammation
Phagocytosis
Complement promotes inflammation and phagocytosis by? (4)
Binds to foreign cells
Destroys cells
Promotes inflammation
Attracts phagocytes
Describe inflammation
A nonspecific defensive response to a tissue damaging irritant
Inflammatory reaction includes
Heat
Redness
Swelling
Pain
What 3 things occur with a fever
Stimulates phagocytes
Increases metabolism
Decreases some organisms ability to multiply
A fever is a sign that
The body’s defense is working
Adaptive immunity is aka
Acquired immunity
Adaptive immunity is stimulated by?
Antigens
What is an antigen
Substance capable of inducing a specific immune response
Antigens stimulate the activity of
T or B cells (lymphocytes)
An antigen is a substance that induces the formation of antibodies because?
It is recognized by the immune system as a threat
Where do T cells originate
In red bone marrow
T cells migrate and mature where
Migrate to the thymus and mature there
T cells provide ?
Cell mediated immunity
T cells are defense against ?
Cancer cells
Viruses
Pathogens that grow within cells
What are the 4 types of T cells
Cytotoxic
Helper
Regulatory
Memory
Cytotoxic T cells directly destroy
Certain abnormal cells
Cytotoxic T cells produce substances that cause cells to self destruct through?
Apoptosis
*tightly regulated cell suicide)
Helper T cells release what?
Stimulate what?
Release interleukins
Stimulate the response of cytotoxic T cells, B cells and macrophages
Helper T cells act on
White blood cells
What do regulatory T cells do?
Suppress the immune response to stop the system from becoming overactive
What do memory T cells do?
Remember an antigen
T cells cannot respond to foreign antigens directly, an antigen must be shown to them by?
An APC (antigen presenting cells)
What are the most important antigen presenting cells (APC)
Dendritic cells (large phagocytic cells with fibrous arms) and macrophages
B Cells originate and mature in?
Red bone marrow
B Cells produce what in response to antigens ?
Antibodies or immunoglobulins
B cells provide?
Humoral immunity
-long term immunity
-protects against circulating antigens and bacteria that grow OUTSIDE the cell
There are 2 types of B cells which are
Plasma cells (secrete antibodies)
Memory B cells
Antibodies are produced in response to a specific antigen and they bind much like a
Lock and key model
Some active B cells don’t become plasma cells but become
Memory cells
Antibodies do what 3 things?
Inhibit the pathogens ability to infect other cells
Neutralize toxins
Promote the activities of other immune agents
What does natural active immunity refer to
Acquired through contact with a specific disease organism
Natural passive immunity refers to
Acquired through transmission of maternal antibodies to fetus and baby
What is a vaccine
A preparation that is administered to stimulate antibody production and T cell activation against a particular pathogen
Vaccines can be made with
Live or dead organisms
There are 4 types of vaccines which are?
Live
Toxoid
Antigenic component or genetically engineered
mRNA Vaccines
A toxoid vaccine is a
Altered toxin used to produce active immunity
Live vaccines are attenuated which means
Attenuated meaning the organism has been weakened for use
-virulence must be reduced to prevent disease
mRNA vaccines do not use?
What does it use?
Does not use A live virus or DNA
It uses messenger RNA to teach our cells how to make a protein that will trigger antibodies
What is an antiserum
Readymade serum that provides short lived effective protection against organisms
quick fix
Antiserums prevent disease in individual with no established immunity who is exposed to?
Virulent organisms
Examples of antiserums
Diptheria
Rabies
Antivenins (snake bite)
Tetanus
What are allergens
Environmental substances that induce hypersensitivity reactions
What is multiple myeloma
Bone marrow tumours
Blood cancer affects
Plasma cells
Multiple myeloma results in?
Lowered resistance to infection
Anemia
Bone pain
Body tissue loss
Kidney failure
Immune surveillance is a theory that the immune system
Recognizes and destroys tumor cells that are constantly arising during the life of the individual
What is rejection syndrome
Immune system destroys the newly transplanted tissue or organs from another person or animal
Rejection syndrome is reduced by
Tissue typing
Immune suppression drugs
