immune system Flashcards
how are invaders recognized when in the body?
They are recognized by antigens
what are antigens
Chemical name tags on the surface of every cell and determines whether they are attackers or not.
how many lines of defense are there?
3 lines of defense.
what are the 3 lines of defense?
First line:barriers
2nd line: non specific patrol
3rd line: immune system
what does the first line of defense do?
First line: barriers
Broad external defense: like walls and moats
the skin, mucus glands, hair and other external stuff.
what does the second line of defense do?
2nd line: non specific patrol
broad, internal defense: patrolling soldiers (white blood cells)
Attack invaders that get through the skin. they
are recognized by reading antigens off the viruses. Phagocyte (eating) WBC’s or macrophages (big eater) eat the viruses.
what does the third line of defense do?
3rd line: immune system
specific, acquired immunity : elite trained units
Recognizes specific foreign antigen on attackers.
Lymphocyte WBCs & antibodies: B& antibodies T cells attack and kill viruses.
what are antibodies?
Antibodies are proteins made by white blood cells (B cells specifically) that tag invaders in the blood so macrophages can eat them.
Tag says “this is an invader”. Almost like biological handcuffs.
antigens are not antibodies. antibodies are tags that say how to destroy them.
what are T cells? what do they do?
T cells are white blood cells which attack invaders. there are two different type of cells. helper T cells, killer T cells and memory T cells.
Helper T cells
Sounds the alarm for the rest of the immune system. Stimulates killer t cells and b cells.
Killer T cells
Destroy infected body cells
they Secrete perforin which is a protein that Punctures cell membrane of infected cell membrane and causing the cell to die, killing the virus along with it.
Memory T cells
Remembers invaders & reacts against it again quickly
they go from bone marrow and mature in the thymus
what are B cells? what do they do?
B cells are white blood cells that create antibodies for the body to use to protect it self against disease later down the line.
Produce specific antibodies, Against specific antigen.
Defense against attackers circulating freely in blood & lymph
there are two types of B cells.
Plasma cells
Immediate production of antibodies
Rapid response, short term release. these are the cells that make the antibodies initially.
Memory cells
Long term immunity
holds the antibodies for later use.
how are T cells and B cells different?
T cells directly attack viruses while B cells dont. they create antibodies instead.
what happens when the immune system fails and attacks itself?
when the immune system attacks its own cells, its called an autoimmune disease. things like diabetes, MS, and lupus happen as a result of that.
why do people get allergies?
allergies occur when people immune systems flag harmless compounds, causing initiations and even anaphylaxis.
what are prions and what do they do?
Prions are proteins which form insoluble deposits in the brain
it Causes neurons to rapidly degeneration.
Mad cow disease (bovine spongiform encephalitis: BSE) is an example.
People in new guinea used to suffer from kuru which they got from eating the brains from their enemies.
