Immune System Flashcards
Immunity
Resistance to infectious disease
What is innate immunity
Resistance that exists prior to exposure to the microbe
How is innate immunity different to acquired immunity
It does not improve after exposure to organism
Give the 1st line of defense for innate immunity
Skin
Mucous membranes and secretions
Normal flora
Give the 2nd line of defense of innate immunity
Innate immune cells
Inflammation
Complement
Antimicrobial substances
What cells is skin made up of
Keratinized cells
How can pathogens lenertrate skin
If there is a broken area of the skin
What does the epithelium of the mucus membrane do
It secretes mucus which trap many microbes and foreign substances
What is gastric juice
It’s a mixture of HCL ,enzymes and mucus and it destroys bacteria
How do eyes protect themselves from bacteria
Lacrimal apparatus produces and drains away tears which contain lysosome ,an enzyme which can break down the cell walls of certain bacteria
Where can we find lysosome
Saliva ,perspiration,nasal secretions and tissue fluids
Interferons
Defense against viral infections by preventing their replication
Complement system
Enhances immune reactions by causing bursting of microbes ,promoting phagocytosis and contributing to inflammation
Iron building proteins
Inhibit the growth of certain bacteria by reducing the amount of available iron
Antimicrobial proteins
Kill a wide range of microbes and attract dendritic cells and mast cells which participate in immune responses
How do natural killer cells attack foreign substances
They bind to a target cell and release granules contains toxic substances from NK cells
Phagocytes
Specialized cells ,They perform phagocytosis
What are the two major types of phagocytes
Neutrophils and macrophages
What are the two types of macrophages
Fixed -constantly stand guard in specific tissues
Wandering -develop during periods of infections from circulating monocytes and become phagocytic
Histiocytes
Macrophages in connective tissue
Kupffer cells
In the liver
What are the steps of phagocytosis
- chemotaxis
- adherence
- ingestion
- digestion
- killing
What are the sigh and symptoms of inflammation
Redness
Pain
Heat
Swelling
What are the 3 stages of inflammation
- vasodilation and increased permeability of blood vessels
- emigration of phagocytes from the blood into interstitial
- Tissue repair
Why does a fever occur
The hypothalamic thermostat is reset
What are the benefits of inflammation
Intensifies effects of interferons ,inhibits bacterial growth ,speeds up tissue repair
What is adaptive immunity
The ability to defend itself against specific invading agents such as bacteria ,toxins ,viruses ,and foreign tissues
Involves B and T lymphocytes
What are the two properties of immunity
Specificity for particular antigens
Memory
What are the two types of adaptive immunity
Cell mediated immunity
Antibody mediated immunity
What is cell mediated immunity
Cytotoxic T cells directly attack invading antigen . Effective against 1.intracellular pathogens 2.cancer cells 3. Foreign tissue transplants
What is antibody mediated immunity
B cells transform into plasma cells which synthesize and secrete proteins called antibodies to inactivate antigens
Effective against :
Extracellular pathogens
Bacteria
Or fungi that are in body fluids outside cells
What do B cells do in adaptive immunity
In adaptive immunity what do B cells do they respond to antigens by becoming plasma. Elks
The plasma cells make antibodies
Some B cells become memory B cells
Where do the B lymphocytes develop
They develop in the B cells
Where do T cells mature
T cells migrate to thymus where they mature
Cytotoxic cells (CD8 )
They protect the body against viruses and cancer cells
Helper T cells (CD4 )
Increase antibody formation,memory cell formation ,B cell formation and phagocytosis
Self recognition
The ability to recognize your own proteins
Self tolerance
The lack of reactivity to peptide fragments from your own proteins
AIDS
A condition in which a person experiences an assortment of infections due to the progressive destruction of immune system cells by HIV
Autoimmune disease
The immune system fails to display self tolerance and attacks the persons own tissues
Examples of autoimmune diseases
Graves’ disease,myasthenia graves ,type 1 diabetes ,RA ,systemic lupus erythmatosus
