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29 Cards in this Set
- Front
- Back
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Pathogen |
An agent that causes disease |
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Antigen |
A foreign particle that triggers an immune response Often are proteins on the surface of viruses and bacteria |
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Non specific defense |
Attack all pathogens and antigens the same way |
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Specific defense |
Immune response that targets pathogens that get past the non specific defense |
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Non specific defense- first line of defense |
Skin- Physical barrier Mucus Membranes- mucus traps pathogens |
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Non specific defense- second line of defense |
Inflammatory response Fever Proteins |
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Inflammatory response |
Damaged cells release histamines Histamines dilate blood vessels Blood vessels leak fluid and white blood cells White blood cells e.g. macrophages, neutrophils and natural killer cells |
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Why is there swelling and redness in an inflammatory response |
excess fluid and blood |
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What is pus? |
Dead neutrophils and other white blood cells |
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What do macrophages do? |
Engulfs and kills pathogens, breaks them down and displays their antigens on MHC-2 proteins |
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What do neutrophils do? |
Engulf pathogens and release chemicals that kill pathogens and themselves |
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What do natural killer cells do? |
- Recognise and kill infected cells and tumors. - Injects with enzymes that trigger apoptosis. (Programmed cell death) - Can tell the difference because of a protein on all healthy (vertebrate) cells surface called MHC-1 |
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What is a fever? |
A fever is a bodily temperature rise response to infection. |
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Pros of fever |
Increases metabolic processes of cells Pathogens like bacteria can't grow well |
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Cons of fever |
Prolonged fever is bad for the body |
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What are complement Proteins? |
Kill pathogens by poking a hole in their membranes |
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What is intrerferon? |
A cytokine that protects cells from virus infections |
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What is the specific defense- third line of defense? |
- Macrophage engulfs pathogen and displays antigen on surface |
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What are phagocytes? |
A cell that engulfs e.g. neutrophils and macrophages |
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What do Helper T cells do? |
Recepter proteins bind to viral antigen displayed on macrophages Causes macrophage to release interleukin-1 Interleukin-1 activates helper T cell to make more helper T cells and memory T cells Activated helper T cells release cytokines that activate cytotoxic T cells and B cells (Raise alarm) |
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What do cytotoxic T cells do? |
Activated by cytokines from activated helper T cells Kills infected cells with antigens on their MHC proteins Recepter binds to proteins Releases enzymes that trigger apoptosis |
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What to B cells do? |
Once a receptor binds to an antigen Activated by cytokines Divides into either plasma cells or memory B cells |
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What do plasma cells do? |
Plasma cells mass produce antibodies that bind to antigens |
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What do antigens do? |
Antigens clump pathogens together to hinder transport Also mark them for destruction |
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Difference between B and T cells? |
B cells fight outside the cells T cells fight inside the cells |
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Difference between memory B cells and memory T cells? |
Memory B cells remember foreign 'substances' Memory T cells remember own misbehaving cells |
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Two phases of specific defense? |
Primary immune response Secondary immune response |
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What is a primary immune response? |
Occurs when the body has never encountered the pathogen before Goes through all the steps and memory cells are made |
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What is a secondary immune response? |
Memory cells identify the invader and antibodies are mass produced destroying the invader before symptoms are felt. The system is immune. |
