Cell recognition and the immune system Flashcards
What type of cell is responsible for detecting non-self cells?
White blood cells called lymphocytes
What happens after a non-self cell is detected?
The lymphocyte triggers an immune response
What are the types of non-self cells lymphocytes can detect?
Pathogens, and toxins produced by pathogens.
Cells from other humans.
Abnormal body cells, e.g. cancer cells.
What are pathogens?
Any microorganisms that cause disease, e.g. bacteria and viruses.
Why does the body sometimes reject transplanted organs?
Lymphocytes identify the cells in the transplanted organ as non-self, and trigger an immune response. Patients often need to take drugs that supress their immune system.
What types of molecules are found in a cell-surface membrane?
Glycoproteins, glycolipids, proteins, cholesterol
Why are proteins useful for distinguishing between cells?
Proteins’ tertiary structure can form a wide variety of shapes.
What is an antigen?
A protein in the cell-surface membrane that triggers an immune response.
How do lymphocytes detect non-self cells?
Lymphocytes have antigen receptors complementary to antigens on non-self cells, which bind with the antigens, activating the lymphocyte and triggering an immune response.
How many antigens can one lymphocyte detect?
A single lymphocyte has only one type of antigen receptor, complementary to one specific antigen. Lymphocytes cause a specific immune response.
What are phagocytes?
Phagocytes are a type of white blood cell that engulf and break down pathogens via phagocytosis.
How do phagocytes detect pathogens?
They are not specific to a particular antigen or pathogen. Instead it has receptors complementary to molecular patterns found on the surface of all pathogens, which they bind to, causing an immune response.
What type of immune response is triggered by lymphocytes and phagocytes?
lymphocytes - specific
phagocytes - non-specific
