Immunological System Physiology 1 Flashcards
What are the 3 types of granulocytes?
Neutrophils
Basophils
Eosinophils
What are the 3 types of agranulocytes?
Lymphocytes
Monocytes
Platelets
Where do thymic precursors come from?
Bone marrow
Which part of the thymus do immature T cells enter?
The subcapsular or outer cortex of the thymus
What is the first receptors thymocytes express?
CD2, which is a T cell specific adhesion molecule
As the thymocytes/immature T cells move into the inner cortex what happens?
They interact with the branching network of epithelial cells and express both CD4 and CD8 receptors (called double-positive T cells)
What is positive selection?
It is a process in cortex where the CD4 and CD8 receptors are tested and only one is maintained on the single-positive T cell
Which type of MHC class do CD4 receptors interact with?
Type II
Which type of MHC class do CD8 receptors interact with?
Type I
What is negative selection?
That is the process by which a T cell is shown a self-peptide in the cortico-medullary junction. If their receptor binds too strongly, then they undergo apoptosis
Where does the final stage T cell develop occur?
In secondary lymphoid tissue
What triggers these naive T cells to divide and differentiate?
Interact with their receptor specific antigen. Naive T cells differentiate to respond and properly take care of a specific antigen.
What do CD4+ T cells further mature into outside the thymus?
T helper 1 or 2 cells
What are B cells derived from?
Pluripotential hemopoietic stem cells
What are the B cell develop stages called?
Early pro-B cell –> late pro-B cell –> pre-B cell –> immature B cell –> mature B cell
What do immature B cells express?
Only IgM. IgM is the first type to be made and has a role of controlling B cell activation.
What can mature or naive B cells express
IgM or IgD. IgD signals B cell activation.
The final stage of B cell maturation occurs where?
Either in the bone marrow or in secondary lymphoid tissue
What is a plasma cell?
A mature B cell that secretes antibodies
What is a memory B cell?
A post-immune-response, differentiated, high-affinity, quick acting B cell, that enables a second encounter with an antigen to be faster and stronger
How does the liver contribute to innate immunity?
(1) Acute phase protein production
(2) Non-specific phagocytosis
(3) Non-specific pinocytosis
(4) Non-specific cell killing