Immune system II Flashcards
Innate immunity is called _______ and adaptive immunity is called ______.
Nonspecific
Specific
What are general protective measures, Always working, functioning without prior exposure to harmful elements?
Nonspecific immunity
What are some systems/processes that contribute to nonspecific immunity?
Skin Mucus Gastric acid and digestive enzymes Chemical compounds in blood/fluids Inflammation response
How does skin contribute to nonspecific immunity? Example?
Is dry and skin cells flake off
Resists incursion by preventing attachment
Has antimicrobial chemicals, eg lactic acid in sweat
How does mucus contribute to nonspecific immunity?
Respiratory passages trap bacteria, viruses, and other foreign material
Where does low pH allow for nonspecific immunity?
Stomach- with gastric acid and digestive enzymes
What is an example of a chemical in bodily fluids that contributes to general immunity
eg, lysozyme- found in tears, saliva, nasal secretions, and perspiration
What is inflammation? (definition with leukocytes)
A local defense response where leukocytes are mobilized to engulf and destroy microbes
What is the process of inflammation at a cellular level?
After microbes invade tissue leads to a localized release of histamine, so vasodilate locally, increasing capillary permeability
↑Blood flow (due to histamine)
Neutrophils and macrophages are attracted to the site by chemotaxis
These cells engulf and destroy microbes
Then remove debris and initiate repair of area
What are four signs of inflammation?
Redness, Swelling, Heat, Pain
Which three cells are involved in immuno phagocytosis?
Neutrophils
Monocytes
“Fixed macrophages”
How do neutrophils and monocytes respond and phagocytize?
Neutrophils are 1st
Monocytes are 2nd, in greater numbers, and turn into macrophages
What are “fixed macrophages”? Examples?
Organ-specific macrophages (stay in organ)
eg Kupffer cell in liver, dust cells in lung
What is a NK cell? In one word, what do they do?
Natural Killer cells (surveillance)
Which cells continually patrol the body on the lookout for pathogens, diseased, or damaged host cells?
NK cells
What cells do NK cells target?
Attack and kill bacteria, cells infected with viruses, cancer cells
What is the mechanism NK cells use to kill?
Bind to cells and release perforins, that create a hole in cell membranes
What is a perforin?
Compound released by NK cells that punch a hole in the membrane of a target cell
What is the complement system?
A group of 30+ globulins made in the liver
They “complete” the action of antibodies
When does specific immunity develop?
Develops after 1st exposure by a foreign substance/toxin
What is the specificity of specific immunity?
Immunity directed against a particular pathogen eg chicken pox
What is the memory of specific immunity?
When re-exposed to the same pathogen, the body will react so quickly that there is no noticeable illness
What is needed for the “memory” of specific immunity to work?
Antigens- Each cell, organ, toxin has specific antigens on its surface
What are the two types of specific immunity?
How are they mediated?
Cellular immunity (cell-mediated) Humoral immunity (antibody-mediated)
In cellular immunity, what the breakdown of cells by type?
80% of lymphocytes are T cells, 5% are NK cells, 15% B cells
What are the different types of T cells?
Tc- cytotoxic T cells
Th- helper T cells
Tr- regulatory T cells
Tm- memory T cells
What does a cytotoxic T cell do?
The only T cells that directly attack and kill other cells
Does cell-to-cell battle
How does a cytotoxic T cell kill other cells?
Lethal hit- Delivers a lethal hit of chemicals, then looks for more to kill
What does a helper T cell do?
Promote the action of T cells
How does a helper T cell promote the actions of cytotoxic T cells?
TH cells recruit more and more TC cells providing an expanded protection
Reads the presented antigen from the APCs (macrophages) and this stimulates the T and B cells to go through mitosis and maturation
What do regulatory T cells do?
Limit the immune response by inhibiting the multiplication of T cells
Make sure T’s don’t go berserk and kill
Not well understood
How many types of memory T cells are there?
2 types: Memory T cell (AND memory B cell, before it becomes a plasma cell)
What are memory T cells defended from?
Cytotoxic T cells
What do memory T cells do?
Responsible for memory in cellular immunity
If you had chicken pox, are now immune due to TM
What cells is used in humoral immunity?
B cells
Humoral immunity is _____-mediated and _____-borne.
Antibody-mediated
Blood-borne
How are antibodies produced?
B cell changes to a plasma cell, which produces antibodies
Where do B cells become immunocompetent?
B cells mature in bone marrow
What is the fork analogy for antibodies?
“Handle” of Y will be the same, “tines” are specific for antigens
What are the three mechanisms of humoral immunity?
Agglutination
Precipitation
Neutralization
What is agglutination?
Causes clumping together of “enemy” cells and pathogens
How does agglutination work against enemy cells?
Immobilizes pathogens so they cannot spread
They then form antigen-antibody complexes (eaten by eosinophil)
What is precipitation?
Antibodies link antigen molecules together
How does precipitation work against enemy cells?
Creates complexes too large to remain in solution (precipitate out)
Are then phagocytized by eosinophil in CT (due to precipitation out)
What is neutralization and how does it work against enemy cells?
Only certain regions of an antigen are pathogenic
Antibodies can neutralize an antigen by covering/masking those active sites
