IMMUNE SYSTEM 2 Flashcards
THE IMMUNE SYSTEM INCLUDES
Antigen Antibody
Antigen
ü Self-antigen
• Only found on the host’s own cells and does not
trigger an immune response
• There is great genetic variability between
individuals
• This antigen is different in other people → it
would cause an immune response
• There is only 1:4 change that siblings will possess
an identical antigen
ü Non-self-antigen
• Found on cells entering the body (e.g. bacteria,
viruses, another person’s cell)
• Will cause an immune response
Antibody
ü Immunoglobin protein
• Secreted by B-lymphocytes and produced in
response to a specific (foreign) non-self antigen
• B-lymphocyte’s receptor site matches the nonself-antigen
• Each antibody is produced by one type of Blymphocyte for only one type of antigen
• An antibody is Y-shaped
• B cells divide and form memory cells and
antibody-secreting plasma cells
Two different immune responses occur
The humoral response
The cell-mediated response
The humoral response
• involves B cells that recognise
antigens or pathogens that are
circulating in the lymph or blood
The cell-mediated response
• involves mostly T cells that recognise and respond to a cell that has already been damaged by activating phagocytes, antigen-specific cytotoxic Tlymphocytes, and the release of various cytokines (in response to that antigen.... )
THE LYMPHATIC SYSTEM
- Plays a vital and central role in immunity
* Produces T-lymphocytes or T cells
THE LYMPHATIC SYSTEM PRODUCES
• Secretes hormone called thymosin
THE LYMPHATIC SYSTEM CONSISTS
Lymph—
üLymphatic vessels—
üLymph nodes
Lymph
fluid in the tissue spaces that carries protein molecules and other substances back to
the blood
üLymphatic vessels
permit only one-way movement of lymph
üLymph nodes
o Filter lymph
o Located in clusters along the pathway of lymphatic vessels
o Functions include defense and WBC formation
