Cells of the immune system Flashcards
What are the 5 main types of white blood cells
Neutrophil
Basophil
Eosinophil
Monocyte
Lymphocyte
What can Haemopoietic stem cells giver rise to?
(7)
Common lymphoid precursor
megakaryocyte
granulocytes
mast cell
monocytes
macrophages
Secondary lymphoid tissues
What does the Lymphoid linage made up of?
Lymphocytes
What is the Myeloid lineage made up of?
What are granulocytes
Myeloid lineage made of Granulocytes and Monocytes.
Granulocytes are:
Neutrophils
Eosinophils
Basophils (Mast cells)
Neutrophil characteristics…
(main 2)
~95% of circulating granulocytes
multi-lobed nucleus
- Adhere to endothelial cells lining blood vessels and squeeze between them to leave circulation and enter tissues (diapedesis)
- Predominant role - phagocytosis and destruction of pathogens
Eosinophils Characteristics..
Bilobed nucleus
Many cytoplasmic granules that stain with eosin
Release of granules upon activation:
- killing of large pathogens
e. g. schistosomula, that cannot be phagocytosed
Basophils Characteristics…
Mast cells share characteristics with basophils but are only found in tissues
Both are triggered by allergens to release the contents of their granules = allergic response
What are mast cells packed with?
Packed with granules which contain Histamine and other inflammatory mediators
What do Lysomes contain?
•Lysosomes contain peroxidase and acid hydrolases – important for killing phagocytosed microorganisms
What is the main function of macrophages?
Major function - disposal of microbes and dead body cells through phagocytosis
What are antigen presenting cells?
Antigen Presenting Cells (APC)
-Present antigen to T cells
What is the role of monocytes and macrophages in immune response?
phagocytosis
take up agtigents process them and present them to T cells
Key roles of lymphocytes?
Play a role in both cellular and humoral immunity
Found in blood, lymph and specialised tissues
Some are very long-lived - MEMORY cells
Where do lymphocytes come from?
All lymphocytes arise in bone marrow from pluripotent stem cell
Further differentiation in primary lymphoid organs
What is used to study cell surfaces?
Monoclonal antibodies are widely used to study cell surfaces
they are Highly specific for one antigenic determinant
Their use in experiments with immune cells
development of a system of nomenclature
= Cluster of Differentiation or CD system
Are lymphocytes specific?
yes Each lymphocyte
- is specific for only one antigenic determinant
- has a specific antigen receptor on surface
how are B and T lymphocytes activated?
encountering an antigen
What happens when Binding of antigen to lymphocyte antigen receptor
clonal selection and expansion
What does CLONAL EXPANSION produce?
CLONAL EXPANSION which produces more
Activated cells
Memory cells
Gives more rapid, more effective response
